diff --git a/.ci/README.md b/.ci/README.md
index 7b8ea3d2a9..72568fd844 100644
--- a/.ci/README.md
+++ b/.ci/README.md
@@ -16,6 +16,7 @@ Test jobs:
 - `test-350-cran-lin` - R 3.5.0 on Linux, no `r-recommended`
 - `test-rel-win` - `r-release` on Windows
 - `test-dev-win` - `r-devel` on Windows
+- `test-old-win` - `r-oldrel` on Windows
 - `test-rel-osx` - MacOSX build not yet deployed, see [#3326](https://github.com/Rdatatable/data.table/issues/3326) for status
 
 Artifacts:
@@ -25,7 +26,7 @@ Artifacts:
 - [html vignettes](https://rdatatable.gitlab.io/data.table/library/data.table/doc/index.html)
 - R packages repository for `data.table` and all _Suggests_ dependencies, url: `https://Rdatatable.gitlab.io/data.table`
   - sources
-  - Windows binaries for `r-release` and `r-devel`
+  - Windows binaries for `r-release`, `r-devel` and `r-oldrel`
 - [CRAN-like homepage](https://rdatatable.gitlab.io/data.table/web/packages/data.table/index.html)
 - [CRAN-like checks results](https://rdatatable.gitlab.io/data.table/web/checks/check_results_data.table.html) - note that all artifacts, including check results page, are being published only when all test jobs successfully pass, thus one will not see an _ERROR_ status there (unless error happened on a job marked as `allow_failure`).
 - [docker images](https://gitlab.com/Rdatatable/data.table/container_registry) - copy/paste-able `docker pull` commands can be found at the bottom of our [CRAN-like homepage](https://rdatatable.gitlab.io/data.table/web/packages/data.table/index.html)
diff --git a/.ci/publish.R b/.ci/publish.R
index fd95947ed4..526d9bd80d 100644
--- a/.ci/publish.R
+++ b/.ci/publish.R
@@ -1,12 +1,17 @@
 format.deps <- function(file, which) {
   deps.raw = read.dcf(file, fields=which)[[1L]]
   if (all(is.na(deps.raw))) return(character())
+  deps.raw = gsub("\n", " ", deps.raw, fixed=TRUE)
   deps.full = trimws(strsplit(deps.raw, ", ", fixed=TRUE)[[1L]])
   deps = trimws(sapply(strsplit(deps.full, "(", fixed=TRUE), `[[`, 1L))
+  deps.full = gsub(">=", "&ge;", deps.full, fixed=TRUE)
+  deps.full = gsub("<=", "&le;", deps.full, fixed=TRUE)
+  if (any(grepl(">", deps.full, fixed=TRUE), grepl("<", deps.full, fixed=TRUE), grepl("=", deps.full, fixed=TRUE)))
+    stop("formatting dependencies version for CRAN-line package website failed because some dependencies have version defined using operators other than >= and <=")
   names(deps.full) <- deps
   base.deps = c("R", unlist(tools:::.get_standard_package_names(), use.names = FALSE))
   ans = sapply(deps, function(x) {
-    if (x %in% base.deps) deps.full[[x]]
+    if (x %in% base.deps) deps.full[[x]] ## base R packages are not linked
     else sprintf("<a href=\"../%s/index.html\">%s</a>", x, deps.full[[x]])
   })
   sprintf("<tr><td>%s:</td><td>%s</td></tr>", which, paste(ans, collapse=", "))
@@ -26,6 +31,39 @@ format.bins <- function(ver, bin_ver, cran.home, os.type, pkg, version, repodir)
   paste(ans[fe], collapse=", ")
 }
 
+format.entry <- function(field, dcf, url=FALSE) {
+  if (field %in% colnames(dcf)) {
+    value = gsub("\n", " ", dcf[,field], fixed=TRUE)
+    if (url) {
+      urls = trimws(strsplit(value, ",", fixed=TRUE)[[1L]])
+      value = paste(sprintf("<a href=\"%s\">%s</a>", urls, urls), collapse=", ")
+    }
+    sprintf("<tr><td>%s:</td><td>%s</td></tr>", field, value)
+  }
+}
+format.maintainer <- function(dcf) {
+  if ("Maintainer" %in% colnames(dcf)) {
+    text2html = function(x) {
+      # https://stackoverflow.com/a/64446320/2490497
+      splitted <- strsplit(x, "")[[1L]]
+      intvalues <- as.hexmode(utf8ToInt(enc2utf8(x)))
+      paste(paste0("&#x", intvalues, ";"), collapse = "")
+    }
+    tmp = gsub("@", " at ", dcf[,"Maintainer"], fixed=TRUE)
+    sep = regexpr("<", tmp, fixed=TRUE)
+    name = trimws(substr(tmp, 1L, sep-1L))
+    mail = text2html(trimws(substr(tmp, sep, nchar(tmp))))
+    sprintf("<tr><td>Maintainer:</td><td>%s  %s</td></tr>", name, mail)
+  }
+}
+format.materials <- function() {
+  return(NULL) ## TODO
+  value = NA
+  #NEWS
+  #README
+  sprintf("<tr><td>Materials:</td><td>%s</td></tr>", value)
+}
+
 package.index <- function(package, lib.loc, repodir="bus/integration/cran") {
   file = system.file("DESCRIPTION", package=package, lib.loc=lib.loc)
   dcf = read.dcf(file)
@@ -40,21 +78,31 @@ package.index <- function(package, lib.loc, repodir="bus/integration/cran") {
     format.deps(file, "LinkingTo"),
     format.deps(file, "Suggests"),
     format.deps(file, "Enhances"),
+    if ("Built" %in% colnames(dcf)) sprintf("<tr><td>Built:</td><td>%s</td></tr>", substr(trimws(strsplit(dcf[,"Built"], ";", fixed=TRUE)[[1L]][[3L]]), 1L, 10L)),
+    if ("Author" %in% colnames(dcf)) sprintf("<tr><td>Author:</td><td>%s</td></tr>", dcf[,"Author"]),
+    format.maintainer(dcf),
+    format.entry("BugReports", dcf, url=TRUE),
+    format.entry("License", dcf),
+    format.entry("URL", dcf, url=TRUE),
+    format.entry("NeedsCompilation", dcf),
+    format.entry("SystemRequirements", dcf),
+    format.materials(), ## TODO
     if (pkg=="data.table") sprintf("<tr><td>Checks:</td><td><a href=\"../../checks/check_results_%s.html\">%s results</a></td></tr>", pkg, pkg)
   )
   vign = tools::getVignetteInfo(pkg, lib.loc=lib.loc)
-  r_bin_ver = Sys.getenv("R_BIN_VERSION")
-  r_devel_bin_ver = Sys.getenv("R_DEVEL_BIN_VERSION")
-  stopifnot(nzchar(r_bin_ver), nzchar(r_devel_bin_ver))
+  r_rel_ver = Sys.getenv("R_REL_VERSION")
+  r_devel_ver = Sys.getenv("R_DEVEL_VERSION")
+  r_oldrel_ver = Sys.getenv("R_OLDREL_VERSION")
+  stopifnot(nzchar(r_rel_ver), nzchar(r_devel_ver), nzchar(r_oldrel_ver))
   cran.home = "../../.."
   tbl.dl = c(
     sprintf("<tr><td> Reference manual: </td><td> <a href=\"%s.pdf\">%s.pdf</a>, <a href=\"%s/library/%s/html/00Index.html\">00Index.html</a> </td></tr>", pkg, pkg, cran.home, pkg),
     if (nrow(vign)) sprintf("<tr><td>Vignettes:</td><td>%s</td></tr>", paste(sprintf("<a href=\"%s/library/data.table/doc/%s\">%s</a><br/>", cran.home, vign[,"PDF"], vign[,"Title"]), collapse="\n")), # location unline cran web/pkg/vignettes to not duplicate content, documentation is in ../../../library
     sprintf("<tr><td> Package source: </td><td> <a href=\"%s/src/contrib/%s_%s.tar.gz\"> %s_%s.tar.gz </a> </td></tr>", cran.home,pkg, version, pkg, version),
-    sprintf("<tr><td> Windows binaries: </td><td> %s </td></tr>", format.bins(ver=c("r-devel","r-release"), bin_ver=c(r_devel_bin_ver,r_bin_ver), cran.home=cran.home, os.type="windows", pkg=pkg, version=version, repodir=repodir)),
-    sprintf("<tr><td> OS X binaries: </td><td> %s </td></tr>", format.bins(ver=c("r-devel","r-release"), bin_ver=c(r_devel_bin_ver, r_bin_ver), cran.home=cran.home, os.type="macosx", pkg=pkg, version=version, repodir=repodir))
+    sprintf("<tr><td> Windows binaries: </td><td> %s </td></tr>", format.bins(ver=c("r-devel","r-release","r-oldrel"), bin_ver=c(r_devel_ver, r_rel_ver, r_oldrel_ver), cran.home=cran.home, os.type="windows", pkg=pkg, version=version, repodir=repodir)),
+    sprintf("<tr><td> macOS binaries: </td><td> %s </td></tr>", format.bins(ver=c("r-release","r-oldrel"), bin_ver=c(r_rel_ver, r_oldrel_ver), cran.home=cran.home, os.type="macosx", pkg=pkg, version=version, repodir=repodir))
   )
-  if (pkg=="data.table") {
+  if (pkg=="data.table") { ## docker images
     registry = Sys.getenv("CI_REGISTRY", "registry.gitlab.com")
     namespace = Sys.getenv("CI_PROJECT_NAMESPACE", "Rdatatable")
     project = Sys.getenv("CI_PROJECT_NAME", "data.table")
@@ -74,7 +122,7 @@ package.index <- function(package, lib.loc, repodir="bus/integration/cran") {
     "<style type=\"text/css\">table td { vertical-align: top; }</style>",
     "</head>",
     "<body>",
-    sprintf("<h2>%s</h2>", dcf[,"Title"]),
+    sprintf("<h2>%s: %s</h2>", pkg, dcf[,"Title"]),
     sprintf("<p>%s</p>", dcf[,"Description"]),
     sprintf("<table summary=\"Package %s summary\">", pkg),
     tbl,
@@ -117,7 +165,48 @@ doc.copy <- function(repodir="bus/integration/cran"){
   c(ans1, ans2)
 }
 
-plat <- function(x) if (grepl("^.*win", x)) "Windows" else if (grepl("^.*osx", x)) "Mac OS X" else "Linux"
+plat <- function(x) if (grepl("^.*win", x)) "Windows" else if (grepl("^.*mac", x)) "macOS" else "Linux"
+
+r.ver <- function(x) {
+  tmp = strsplit(x, "-", fixed=TRUE)[[1L]]
+  if (length(tmp) < 2L) stop("test job names must be test-[r.version]-...")
+  v = tmp[2L]
+  if (identical(v, "rel")) "r-release"
+  else if (identical(v, "dev")) "r-devel"
+  else if (identical(v, "old")) "r-oldrel"
+  else {
+    if (grepl("\\D", v)) stop("second word in test job name must be rel/dev/old or numbers of R version")
+    paste0("r-", paste(strsplit(v, "")[[1L]], collapse="."))
+  }
+}
+
+# this for now is constant but when we move to independent pipelines (commit, daily, weekly) those values can be different
+pkg.version <- function(job, pkg) {
+  dcf = read.dcf(file.path("bus", job, paste(pkg, "Rcheck", sep="."), pkg, "DESCRIPTION"))
+  dcf[,"Version"]
+}
+pkg.revision <- function(job, pkg) {
+  dcf = read.dcf(file.path("bus", job, paste(pkg, "Rcheck", sep="."), pkg, "DESCRIPTION"))
+  if ("Revision" %in% colnames(dcf)) {
+    proj.url = Sys.getenv("CI_PROJECT_URL", "")
+    if (!nzchar(proj.url)) {
+      warning("pkg.revision was designed to be run on GLCI where CI_PROJECT_URL var is set, links to commits will not be produced for checks table")
+      substr(dcf[,"Revision"], 1, 7)
+    } else {
+      sprintf("<a href=\"%s\">%s</a>", file.path(proj.url, "-", "commit", dcf[,"Revision"]), substr(dcf[,"Revision"], 1, 7))
+    }
+  } else ""
+}
+pkg.flags <- function(job, pkg) {
+  cc = file.path("bus", job, paste(pkg, "Rcheck", sep="."), pkg, "cc") ## data.table style cc file
+  if (file.exists(cc)) {
+    d = readLines(cc)
+    w.cflags = substr(d, 1, 7)=="CFLAGS="
+    if (sum(w.cflags)==1L)
+      return(sub("CFLAGS=", "", d[w.cflags], fixed=TRUE))
+  }
+  ""
+}
 
 check.copy <- function(job, repodir="bus/integration/cran"){
   dir.create(job.checks<-file.path(repodir, "web", "checks", pkg<-"data.table", job), recursive=TRUE);
@@ -146,6 +235,39 @@ check.copy <- function(job, repodir="bus/integration/cran"){
   setNames(file.exists(file.path(job.checks, c(inst.check, routs))), c(inst.check, routs))
 }
 
+check.flavors <- function(jobs, repodir="bus/integration/cran") {
+  th = "<th>Flavor</th><th>R Version</th><th>OS Type</th><th>CPU Type</th><th>OS Info</th><th>CPU Info</th><th>Compilers</th>"
+  tbl = sprintf(
+    "<tr><td>%s</td><td>%s</td><td>%s</td><td>%s</td><td>%s</td><td>%s</td><td>%s</td></tr>",
+    sub("test-", "", jobs, fixed=TRUE),
+    sapply(jobs, r.ver),
+    sapply(jobs, plat),
+    "", # "x86_64"
+    "", # "Debian GNU/Linux testing"
+    "", # "2x 8-core Intel(R) Xeon(R) CPU E5-2690 0 @ 2.90GHz"
+    "" # "GCC 10.2.0 (Debian 10.2.0-13)"
+  )
+  file = file.path(repodir, "web/checks", "check_flavors.html")
+  writeLines(c(
+    "<html>",
+    "<head>",
+    "<title>Package Check Flavors</title>",
+    "<link rel=\"stylesheet\" type=\"text/css\" href=\"../CRAN_web.css\"/>",
+    "<meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\"/>",
+    "</head>",
+    "<body lang=\"en\">",
+    "<h2>Package Check Flavors</h2>",
+    sprintf("<p>Last updated on %s.</p>", format(Sys.time(), usetz=TRUE)),
+    "<table border=\"1\" summary=\"CRAN check flavors.\">",
+    "<tr>",th,"</tr>",
+    tbl,
+    "</table>",
+    "</body>",
+    "</html>"
+  ), file)
+  setNames(file.exists(file), file)
+}
+
 check.index <- function(pkg, jobs, repodir="bus/integration/cran") {
   status = function(x) if (grepl("^.*ERROR", x)) "ERROR" else if (grepl("^.*WARNING", x)) "WARNING" else if (grepl("^.*NOTE", x)) "NOTE" else if (grepl("^.*OK", x)) "OK" else NA_character_
   test.files = function(job, files, trim.name=FALSE, trim.exts=0L, pkg="data.table") {
@@ -186,30 +308,36 @@ check.index <- function(pkg, jobs, repodir="bus/integration/cran") {
     }
     memouts
   })
-  tbl = sprintf("<tr><td>%s</td><td>%s</td><td><a href=\"%s/%s/00install.out\">out</a></td><td><a href=\"%s/%s/00check.log\">%s</a></td><td>%s</td><td>%s</td></tr>",
-                sub("test-", "", jobs, fixed=TRUE),
-                sapply(jobs, plat),
-                pkg, jobs,
-                pkg, jobs, sapply(sapply(jobs, check.test, pkg="data.table"), status),
-                mapply(test.files, jobs, routs, trim.exts=2L), # 1st fail, 2nd Rout, keep just: tests_x64/main
-                mapply(test.files, jobs, memouts, trim.name=TRUE))
+  th = "<th>Flavor</th><th>Version</th><th>Revision</th><th>Install</th><th>Status</th><th>Flags</th><th>Rout.fail</th><th>Memtest</th>"
+  tbl = sprintf(
+    "<tr><td><a href=\"check_flavors.html\">%s</a></td><td>%s</td><td>%s</td><td><a href=\"%s/%s/00install.out\">out</a></td><td><a href=\"%s/%s/00check.log\">%s</a></td><td>%s</td><td>%s</td><td>%s</td></tr>",
+    sub("test-", "", jobs, fixed=TRUE),
+    sapply(jobs, pkg.version, pkg),
+    sapply(jobs, pkg.revision, pkg),
+    pkg, jobs, ## install
+    pkg, jobs, sapply(sapply(jobs, check.test, pkg="data.table"), status), ## check
+    sapply(jobs, pkg.flags, pkg),
+    mapply(test.files, jobs, routs, trim.exts=2L), # 1st fail, 2nd Rout, keep just: tests_x64/main
+    mapply(test.files, jobs, memouts, trim.name=TRUE)
+  )
   file = file.path(repodir, "web/checks", sprintf("check_results_%s.html", pkg))
-  writeLines(c("<html>",
-               "<head>",
-               sprintf("<title>Package Check Results for Package %s</title>", pkg),
-               "<link rel=\"stylesheet\" type=\"text/css\" href=\"../CRAN_web.css\"/>",
-               "<meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\"/>",
-               "</head>",
-               "<body lang=\"en\">",
-               sprintf("<h2>Package Check Results for Package <a href=\"../packages/%s/index.html\"> %s </a> </h2>", pkg, pkg),
-               sprintf("<p>Last updated on %s.</p>", format(Sys.time(), usetz=TRUE)),
-               sprintf("<table border=\"1\" summary=\"CRAN check results for package %s\">", pkg),
-               "<tr><th>Test job</th><th>OS type</th><th>Install</th><th>Check</th><th>Rout.fail</th><th>Memtest</th></tr>",
-               tbl,
-               "</table>",
-               "</body>",
-               "</html>"),
-             file)
+  writeLines(c(
+    "<html>",
+    "<head>",
+    sprintf("<title>Package Check Results for Package %s</title>", pkg),
+    "<link rel=\"stylesheet\" type=\"text/css\" href=\"../CRAN_web.css\"/>",
+    "<meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\"/>",
+    "</head>",
+    "<body lang=\"en\">",
+    sprintf("<h2>Package Check Results for Package <a href=\"../packages/%s/index.html\"> %s </a> </h2>", pkg, pkg),
+    sprintf("<p>Last updated on %s.</p>", format(Sys.time(), usetz=TRUE)),
+    sprintf("<table border=\"1\" summary=\"CRAN check results for package %s\">", pkg),
+    "<tr>",th,"</tr>",
+    tbl,
+    "</table>",
+    "</body>",
+    "</html>"
+  ), file)
   setNames(file.exists(file), file)
 }
 
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 9a5b4845f8..02b1471f52 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -6,6 +6,9 @@ variables:
   TZ: "UTC"  ## to avoid 'Failed to create bus connection' from timedatectl via Sys.timezone() on Docker with R 3.4.
              ## Setting TZ for all GLCI jobs to isolate them from timezone. We could have a new GLCI job to test under
              ## a non-UTC timezone, although, that's what we do routinely in dev.
+  R_REL_VERSION: "4.0"
+  R_DEVEL_VERSION: "4.1"
+  R_OLDREL_VERSION: "3.6"
 
 stages:
   - dependencies
@@ -16,12 +19,12 @@ stages:
 
 .artifacts-template: &artifacts
   artifacts:
-    expire_in: 4 weeks
+    expire_in: 2 weeks
     when: always
     paths:
       - bus
 
-mirror-packages: ## mirror all recursive dependencies, source and win.binary, of data.table suggests and integration suggests from inst/tests/tests-DESCRIPTION
+mirror-packages: ## mirror all recursive dependencies, source and win.binary of data.table suggests from inst/tests/tests-DESCRIPTION
   stage: dependencies
   tags:
     - linux
@@ -29,15 +32,26 @@ mirror-packages: ## mirror all recursive dependencies, source and win.binary, of
   cache:
     paths:
       - bus/$CI_BUILD_NAME/cran
-  variables:
-    R_BIN_VERSION: "4.0"
-    R_DEVEL_BIN_VERSION: "4.1"
   script:
     - echo 'source(".ci/ci.R")' >> .Rprofile
     - mkdir -p bus/$CI_BUILD_NAME/cran/src/contrib
-    - Rscript -e 'mirror.packages(dcf.dependencies(c("DESCRIPTION","inst/tests/tests-DESCRIPTION"), "all"), repos=c(Sys.getenv("CRAN_MIRROR"), dcf.repos("inst/tests/tests-DESCRIPTION")), repodir="bus/mirror-packages/cran")'
+    - Rscript -e 'mirror.packages(dcf.dependencies("DESCRIPTION", "all"), repos=Sys.getenv("CRAN_MIRROR"), repodir="bus/mirror-packages/cran")'
     - rm bus/$CI_BUILD_NAME/cran/src/contrib/PACKAGES.rds ## fallback to PACKAGES dcf so available.packages:3.4.4 works
-    - Rscript -e 'sapply(simplify=FALSE, setNames(nm=Sys.getenv(c("R_BIN_VERSION","R_DEVEL_BIN_VERSION"))), function(binary.ver) mirror.packages(type="win.binary", dcf.dependencies("DESCRIPTION", "all"), repos=Sys.getenv("CRAN_MIRROR"), repodir="bus/mirror-packages/cran", binary.ver=binary.ver))'
+    - Rscript -e 'sapply(simplify=FALSE, setNames(nm=Sys.getenv(c("R_REL_VERSION","R_DEVEL_VERSION","R_OLDREL_VERSION"))), function(binary.ver) mirror.packages(type="win.binary", dcf.dependencies("DESCRIPTION", "all"), repos=Sys.getenv("CRAN_MIRROR"), repodir="bus/mirror-packages/cran", binary.ver=binary.ver))'
+  <<: *artifacts
+
+mirror-other-packages: ## mirror integration suggests from inst/tests/tests-DESCRIPTION
+  stage: dependencies
+  tags:
+    - linux
+  image: registry.gitlab.com/jangorecki/dockerfiles/r-base-dev
+  cache:
+    paths:
+      - bus/$CI_BUILD_NAME/cran
+  script:
+    - echo 'source(".ci/ci.R")' >> .Rprofile
+    - mkdir -p bus/$CI_BUILD_NAME/cran/src/contrib
+    - Rscript -e 'mirror.packages(dcf.dependencies("inst/tests/tests-DESCRIPTION", "all"), repos=c(Sys.getenv("CRAN_MIRROR"), dcf.repos("inst/tests/tests-DESCRIPTION")), repodir="bus/mirror-other-packages/cran")'
   <<: *artifacts
 
 build: ## build data.table sources as tar.gz archive
@@ -45,8 +59,7 @@ build: ## build data.table sources as tar.gz archive
   tags:
     - linux
   image: registry.gitlab.com/jangorecki/dockerfiles/r-builder
-  dependencies:
-    - mirror-packages
+  needs: ["mirror-packages"]
   before_script:
     - Rscript -e 'install.packages("knitr", repos=file.path("file:",normalizePath("bus/mirror-packages/cran")), quiet=TRUE)'
     - rm -r bus
@@ -80,20 +93,23 @@ build: ## build data.table sources as tar.gz archive
   - rm.exe $(ls.exe -1t data.table_*.tar.gz | head.exe -n 1)
 
 .test-mv-bin-win: &mv-bin-win
-  - mkdir.exe -p cran/bin/windows/contrib/$R_BIN_VERSION; mv.exe $(ls.exe -1t data.table_*.zip | head.exe -n 1) cran/bin/windows/contrib/$R_BIN_VERSION
+  - mkdir.exe -p cran/bin/windows/contrib/$R_VERSION; mv.exe $(ls.exe -1t data.table_*.zip | head.exe -n 1) cran/bin/windows/contrib/$R_VERSION
 
 .test-install-r-rel-win: &install-r-rel-win
-  - curl.exe -s -o ../R-win.exe https://cloud.r-project.org/bin/windows/base/old/4.0.0/R-4.0.0-win.exe; Start-Process -FilePath ..\R-win.exe -ArgumentList "/VERYSILENT /DIR=C:\R" -NoNewWindow -Wait
-.test-install-r-dev-win: &install-r-dev-win
+  - curl.exe -s -o ../R-rel.exe https://cloud.r-project.org/bin/windows/base/old/4.0.3/R-4.0.3-win.exe; Start-Process -FilePath ..\R-rel.exe -ArgumentList "/VERYSILENT /DIR=C:\R" -NoNewWindow -Wait
+.test-install-r-devel-win: &install-r-devel-win
   - curl.exe -s -o ../R-devel.exe https://cloud.r-project.org/bin/windows/base/R-devel-win.exe; Start-Process -FilePath ..\R-devel.exe -ArgumentList "/VERYSILENT /DIR=C:\R" -NoNewWindow -Wait
+.test-install-r-oldrel-win: &install-r-oldrel-win
+  - curl.exe -s -o ../R-oldrel.exe https://cloud.r-project.org/bin/windows/base/old/3.6.3/R-3.6.3-win.exe; Start-Process -FilePath ..\R-oldrel.exe -ArgumentList "/VERYSILENT /DIR=C:\R" -NoNewWindow -Wait
+
 .test-install-rtools-win: &install-rtools-win
   - curl.exe -s -o ../rtools.exe https://cloud.r-project.org/bin/windows/Rtools/rtools40-x86_64.exe; Start-Process -FilePath ..\rtools.exe -ArgumentList "/VERYSILENT /DIR=C:\rtools40" -NoNewWindow -Wait
+.test-install-rtools35-win: &install-rtools35-win
+  - curl.exe -s -o ../Rtools35.exe https://cloud.r-project.org/bin/windows/Rtools/Rtools35.exe; Start-Process -FilePath ..\Rtools35.exe -ArgumentList "/VERYSILENT /DIR=C:\Rtools" -NoNewWindow -Wait
 
 .test-template: &test
   stage: test
-  dependencies:
-    - mirror-packages
-    - build
+  needs: ["mirror-packages","build"]
   <<: *artifacts
 
 .test-lin-template: &test-lin
@@ -122,14 +138,15 @@ build: ## build data.table sources as tar.gz archive
     - windows
     - shared-windows
 
-.test-osx-template: &test-osx
-  <<: *test
-  tags:
-    - macosx
+#.test-mac-template: &test-mac
+#  <<: *test
+#  tags:
+#    - macosx
 
 test-rel-lin: ## most comprehensive tests, force all suggests, also integration tests, using gcc -O3 -flto -fno-common -Wunused-result
   <<: *test-lin
   image: registry.gitlab.com/jangorecki/dockerfiles/r-builder
+  needs: ["mirror-packages","mirror-other-packages","build"]
   variables:
     _R_CHECK_CRAN_INCOMING_: "FALSE"
     _R_CHECK_CRAN_INCOMING_REMOTE_: "FALSE"
@@ -138,7 +155,7 @@ test-rel-lin: ## most comprehensive tests, force all suggests, also integration
     OPENBLAS_MAIN_FREE: "1"
     TEST_DATA_TABLE_WITH_OTHER_PACKAGES: "TRUE"
   before_script:
-    - Rscript -e 'source(".ci/ci.R"); install.packages(dcf.dependencies(c("DESCRIPTION","inst/tests/tests-DESCRIPTION"), which="all"), quiet=TRUE)'
+    - Rscript -e 'source(".ci/ci.R"); install.packages(dcf.dependencies(c("DESCRIPTION","inst/tests/tests-DESCRIPTION"), which="all"), quiet=TRUE, repos=c(getOption("repos"), file.path("file:", normalizePath("bus/mirror-other-packages/cran", mustWork=FALSE))))'
     - *cp-src
     - rm -r bus
     - mkdir -p ~/.R
@@ -225,7 +242,7 @@ test-350-cran-lin: ## R-3.5.0 on Linux, first R altrep version
 test-rel-win: ## R-release on Windows, test and build binaries
   <<: *test-win
   variables:
-    R_BIN_VERSION: "4.0"
+    R_VERSION: "$R_REL_VERSION"
   before_script:
     - *install-r-rel-win
     - *install-rtools-win
@@ -244,9 +261,9 @@ test-rel-win: ## R-release on Windows, test and build binaries
 test-dev-win: ## R-devel on Windows
   <<: *test-win
   variables:
-    R_BIN_VERSION: "4.1"
+    R_VERSION: "$R_DEVEL_VERSION"
   before_script:
-    - *install-r-dev-win
+    - *install-r-devel-win
     - *install-rtools-win
     - $ENV:PATH = "C:\R\bin;C:\rtools40\usr\bin;$ENV:PATH"
     - *install-deps-win
@@ -260,9 +277,29 @@ test-dev-win: ## R-devel on Windows
     - *rm-src-win
     - *mv-bin-win
 
-#test-rel-osx: ## R-release on MacOS, no macosx runner yet
+test-old-win: ## R-oldrel on Windows
+  <<: *test-win
+  variables:
+    R_VERSION: "$R_OLDREL_VERSION"
+  before_script:
+    - *install-r-oldrel-win
+    - *install-rtools35-win
+    - $ENV:PATH = "C:\R\bin;C:\Rtools\bin;$ENV:PATH"
+    - *install-deps-win
+    - *cp-src-win
+    - rm.exe -r bus
+  script:
+    - *mv-src-win
+    - cd bus/$CI_BUILD_NAME
+    - R.exe CMD check --no-manual --ignore-vignettes $(ls.exe -1t data.table_*.tar.gz | head.exe -n 1)
+    - R.exe CMD INSTALL --build $(ls.exe -1t data.table_*.tar.gz | head.exe -n 1)
+    - *rm-src-win
+    - *mv-bin-win
+
+#test-rel-mac: ## R-release on MacOS, no macosx runner yet
+#  <<: *test-mac
 #  variables:
-#    R_BIN_VERSION: "4.0"
+#    R_VERSION: "$R_REL_VERSION"
 #  before_script:
 #    - *install-deps
 #    - *cp-src
@@ -272,9 +309,10 @@ test-dev-win: ## R-devel on Windows
 #    - cd bus/$CI_BUILD_NAME
 #    - R CMD check $(ls -1t data.table_*.tar.gz | head -n 1)
 #    - R CMD INSTALL --build $(ls -1t data.table_*.tar.gz | head -n 1)
-#    - mkdir -p cran/bin/macosx/el-capitan/contrib/$R_BIN_VERSION
-#    - mv $(ls -1t data.table_*.tgz | head -n 1) cran/bin/macosx/el-capitan/contrib/$R_BIN_VERSION
+#    - mkdir -p cran/bin/macosx/el-capitan/contrib/$R_VERSION
+#    - mv $(ls -1t data.table_*.tgz | head -n 1) cran/bin/macosx/el-capitan/contrib/$R_VERSION
 #    - *rm-src
+#    - *mv-bin-mac
 
 integration: ## merging all artifacts to produce single R repository, documentation and website
   stage: integration
@@ -283,22 +321,7 @@ integration: ## merging all artifacts to produce single R repository, documentat
     - linux
   only:
     - master
-  dependencies:
-    - mirror-packages
-    - build
-    - test-rel-lin
-    - test-rel-cran-lin
-    - test-dev-cran-lin
-    - test-rel-vanilla-lin
-    - test-310-cran-lin
-    - test-344-cran-lin
-    - test-350-cran-lin
-    - test-rel-win
-    - test-dev-win
-    #- test-rel-osx
-  variables:
-    R_BIN_VERSION: "4.0"
-    R_DEVEL_BIN_VERSION: "4.1"
+  needs: ["mirror-packages","build","test-rel-lin","test-rel-cran-lin","test-dev-cran-lin","test-rel-vanilla-lin","test-310-cran-lin","test-344-cran-lin","test-350-cran-lin","test-rel-win","test-dev-win","test-old-win"]
   script:
     - Rscript -e 'pkgdown::build_site(override=list(destination="./pkgdown"))'
     ## html manual, vignettes, repos, cran_web, cran_checks
@@ -309,10 +332,12 @@ integration: ## merging all artifacts to produce single R repository, documentat
     - mkdir -p bus/$CI_BUILD_NAME
     ## delete any existing non-dev version of data.table
     - rm -f bus/mirror-packages/cran/src/contrib/data.table_*.tar.gz
-    - rm -f bus/mirror-packages/cran/bin/windows/contrib/$R_BIN_VERSION/data.table_*.zip
-    - rm -f bus/mirror-packages/cran/bin/windows/contrib/$R_DEVEL_BIN_VERSION/data.table_*.zip
-    #- rm -f bus/mirror-packages/cran/bin/macosx/el-capitan/contrib/$R_BIN_VERSION/data.table_*.tgz
-    #- rm -f bus/mirror-packages/cran/bin/macosx/el-capitan/contrib/$R_DEVEL_BIN_VERSION/data.table_*.tgz
+    - rm -f bus/mirror-packages/cran/bin/windows/contrib/$R_REL_VERSION/data.table_*.zip
+    - rm -f bus/mirror-packages/cran/bin/windows/contrib/$R_DEVEL_VERSION/data.table_*.zip
+    - rm -f bus/mirror-packages/cran/bin/windows/contrib/$R_OLDREL_VERSION/data.table_*.zip
+    #- rm -f bus/mirror-packages/cran/bin/macosx/el-capitan/contrib/$R_REL_VERSION/data.table_*.tgz
+    #- rm -f bus/mirror-packages/cran/bin/macosx/el-capitan/contrib/$R_DEVEL_VERSION/data.table_*.tgz
+    #- rm -f bus/mirror-packages/cran/bin/macosx/el-capitan/contrib/$R_OLDREL_VERSION/data.table_*.tgz
     ## merge mirror-packages and R devel packages
     - mv bus/mirror-packages/cran bus/$CI_BUILD_NAME/
     ## publish package sources
@@ -320,17 +345,21 @@ integration: ## merging all artifacts to produce single R repository, documentat
     - mv $(ls -1t bus/build/cran/src/contrib/data.table_*.tar.gz | head -n 1) bus/$CI_BUILD_NAME/cran/src/contrib
     - Rscript -e 'tools::write_PACKAGES(contrib.url("bus/integration/cran", type="source"), type="source", fields="Revision", addFiles=TRUE)'
     ## publish binaries
-    - Rscript -e 'move.bin("test-rel-win", Sys.getenv("R_BIN_VERSION"), os.type="windows")'
-    - Rscript -e 'move.bin("test-dev-win", Sys.getenv("R_DEVEL_BIN_VERSION"), os.type="windows", silent=TRUE)'
-    - Rscript -e 'tools::write_PACKAGES(contrib.url("bus/integration/cran", type="win.binary", ver=Sys.getenv("R_BIN_VERSION")), type="win.binary", fields="Revision", addFiles=TRUE)'
-    - Rscript -e 'tools::write_PACKAGES(contrib.url("bus/integration/cran", type="win.binary", ver=Sys.getenv("R_DEVEL_BIN_VERSION")), type="win.binary", fields="Revision", addFiles=TRUE)'
-    #- Rscript -e 'move.bin("test-rel-osx", Sys.getenv("R_BIN_VERSION"), os.type="macosx")'
-    #- Rscript -e 'move.bin("test-dev-osx", Sys.getenv("R_DEVEL_BIN_VERSION"), os.type="macosx", silent=TRUE)'
-    #- Rscript -e 'tools::write_PACKAGES(contrib.url("bus/integration/cran", type="mac.binary.el-capitan", ver=Sys.getenv("R_BIN_VERSION")), type="mac.binary.el-capitan", fields="Revision", addFiles=TRUE)'
-    #- Rscript -e 'tools::write_PACKAGES(contrib.url("bus/integration/cran", type="mac.binary.el-capitan", ver=Sys.getenv("R_DEVEL_BIN_VERSION")), type="mac.binary.el-capitan", fields="Revision", addFiles=TRUE)'
+    - Rscript -e 'move.bin("test-rel-win", Sys.getenv("R_REL_VERSION"), os.type="windows")'
+    - Rscript -e 'move.bin("test-dev-win", Sys.getenv("R_DEVEL_VERSION"), os.type="windows")'
+    - Rscript -e 'move.bin("test-old-win", Sys.getenv("R_OLDREL_VERSION"), os.type="windows")'
+    - Rscript -e 'tools::write_PACKAGES(contrib.url("bus/integration/cran", type="win.binary", ver=Sys.getenv("R_REL_VERSION")), type="win.binary", fields="Revision", addFiles=TRUE)'
+    - Rscript -e 'tools::write_PACKAGES(contrib.url("bus/integration/cran", type="win.binary", ver=Sys.getenv("R_DEVEL_VERSION")), type="win.binary", fields="Revision", addFiles=TRUE)'
+    - Rscript -e 'tools::write_PACKAGES(contrib.url("bus/integration/cran", type="win.binary", ver=Sys.getenv("R_OLDREL_VERSION")), type="win.binary", fields="Revision", addFiles=TRUE)'
+    #- Rscript -e 'move.bin("test-rel-mac", Sys.getenv("R_REL_VERSION"), os.type="macosx")'
+    #- Rscript -e 'move.bin("test-dev-mac", Sys.getenv("R_DEVEL_VERSION"), os.type="macosx")'
+    #- Rscript -e 'move.bin("test-old-mac", Sys.getenv("R_OLDREL_VERSION"), os.type="macosx")'
+    #- Rscript -e 'tools::write_PACKAGES(contrib.url("bus/integration/cran", type="mac.binary.el-capitan", ver=Sys.getenv("R_REL_VERSION")), type="mac.binary.el-capitan", fields="Revision", addFiles=TRUE)'
+    #- Rscript -e 'tools::write_PACKAGES(contrib.url("bus/integration/cran", type="mac.binary.el-capitan", ver=Sys.getenv("R_DEVEL_VERSION")), type="mac.binary.el-capitan", fields="Revision", addFiles=TRUE)'
+    #- Rscript -e 'tools::write_PACKAGES(contrib.url("bus/integration/cran", type="mac.binary.el-capitan", ver=Sys.getenv("R_OLDREL_VERSION")), type="mac.binary.el-capitan", fields="Revision", addFiles=TRUE)'
     ## install all pkgs to render html and double check successful installation of all devel packages
-    - mkdir -p /tmp/opencran/library /tmp/opencran/doc/html
-    - Rscript -e 'install.packages("data.table", dependencies=TRUE, lib="/tmp/opencran/library", repos=file.path("file:",normalizePath("bus/integration/cran")), INSTALL_opts="--html", quiet=TRUE)'
+    - mkdir -p /tmp/opencran/library /tmp/opencran/doc/html ## reset R_LIBS_USER to re-install all with html because pkgdown image has pre installed curl knitr
+    - R_LIBS_USER="" Rscript -e 'install.packages("data.table", dependencies=TRUE, lib="/tmp/opencran/library", repos=file.path("file:",normalizePath("bus/integration/cran")), INSTALL_opts="--html", quiet=TRUE)'
     - Rscript -e 'packageVersion("data.table", lib.loc="/tmp/opencran/library")'
     ## CRAN style web/CRAN_web.css
     - wget -q -P bus/integration/cran/web https://cran.r-project.org/web/CRAN_web.css
@@ -349,6 +378,8 @@ integration: ## merging all artifacts to produce single R repository, documentat
     - Rscript -e 'pdf.copy("data.table", "test-rel-lin")'
     ## web/checks/check_results_$pkg.html
     - Rscript -e 'check.index("data.table", names(test.jobs))'
+    ## web/checks/check_flavors.html
+    - Rscript -e 'check.flavors(names(test.jobs))'
     ## pkgdown merge
     - Rscript -e 'common_files<-function(path1, path2) intersect(list.files(path1, all.files=TRUE, no..=TRUE), list.files(path2, all.files=TRUE, no..=TRUE)); msg = if (length(f<-common_files("pkgdown","bus/integration/cran"))) paste(c("Following artifacts will be overwritten by pkgdown artifacts:", paste0("  ", f)), collapse="\n") else "No overlapping files from pkgdown artifacts"; message(msg); q("no")'
     - mv pkgdown/* bus/integration/cran/
@@ -366,8 +397,10 @@ integration: ## merging all artifacts to produce single R repository, documentat
   image: docker
   services:
     - docker:dind
-  dependencies:
-    - build
+  needs:
+    - job: build
+    - job: integration
+      artifacts: false
   before_script:
     - sed "s/SRC_IMAGE_NAME/$SRC_IMAGE_NAME/" < .ci/Dockerfile.in > Dockerfile
     - docker login -u gitlab-ci-token -p $CI_JOB_TOKEN $CI_REGISTRY
@@ -420,13 +453,12 @@ pages: ## publish R repository, test jobs summaries, html documentation of all p
   only:
     - master
   image: ubuntu
-  dependencies:
-    - integration
+  needs: ["integration"]
   script:
     - mkdir -p public
     - cp -r bus/integration/cran/* public
     - cat public/src/contrib/PACKAGES
   artifacts: ## publish only when no failure
-    expire_in: 4 weeks
+    expire_in: 2 weeks
     paths:
       - public
diff --git a/inst/tests/other.Rraw b/inst/tests/other.Rraw
index 55718e23b4..1bd91286f9 100644
--- a/inst/tests/other.Rraw
+++ b/inst/tests/other.Rraw
@@ -10,7 +10,7 @@ if (!"package:data.table" %in% search()) stop("data.table should be already atta
 test = data.table:::test
 INT = data.table:::INT
 
-pkgs = c("ggplot2", "hexbin", "plyr", "caret", "xts", "gdata", "zoo", "nlme", "bit64", "knitr", "plm", "parallel")
+pkgs = c("ggplot2", "hexbin", "plyr", "caret", "xts", "gdata", "zoo", "nlme", "bit64", "knitr", "parallel")
 if (any(duplicated(pkgs))) stop("Packages defined to be loaded for integration tests in 'inst/tests/other.Rraw' contains duplicates.")
 
 is.require = function(pkg) suppressWarnings(suppressMessages(isTRUE(require(pkg, character.only=TRUE, quietly=TRUE, warn.conflicts=FALSE))))
@@ -155,15 +155,6 @@ if (loaded[["knitr"]]) {
   test(11, kable(DT), output="x.*y.*1.*2")
 }
 
-# for plm package
-if (loaded[["plm"]]) {
-  set.seed(45L)
-  x  = data.table(V1=c(1L,2L), V2=LETTERS[1:3], V3=round(rnorm(4),4), V4=1:12)
-  px = pdata.frame(x, index=c("V2", "V4"), drop.index=FALSE, row.names=TRUE)
-  test(12.1, class(as.data.table(px)), class(x))
-  test(12.2, class(setDT(px)), class(x))
-}
-
 if (loaded[["parallel"]]) {
   #1745 and #1727
   if (.Platform$OS.type=="windows") {
@@ -200,7 +191,3 @@ test(14.1, !inherits(res, 'error'))
 res = tryCatch(example('CJ', package='data.table', local=TRUE))
 test(14.2, !inherits(res, 'error'))
 
-
-###################################
-#  Add new tests above this line  #
-###################################
diff --git a/inst/tests/tests-DESCRIPTION b/inst/tests/tests-DESCRIPTION
index edfadceb0b..35e3411ad0 100644
--- a/inst/tests/tests-DESCRIPTION
+++ b/inst/tests/tests-DESCRIPTION
@@ -4,4 +4,4 @@ Type: Backend
 Title: List of data.table dependencies used in integration tests
 Authors@R: c(person("data.table team", role = c("aut", "cre", "cph"), email="mattjdowle@gmail.com"))
 Description: Standalone R DESCRIPTION file which defines R dependencies for integration tests of data.table package. Integration tests are not part of main testing workflow. They are performed only when TEST_DATA_TABLE_WITH_OTHER_PACKAGES environment variable is set to true. This allows us to run those integration tests in our CI pipeline and not impose dependency chains on the user.
-Suggests: ggplot2 (>= 0.9.0), reshape, hexbin, fastmatch, nlme, gdata, caret, plm, rmarkdown, parallel
+Suggests: ggplot2 (>= 0.9.0), reshape, hexbin, fastmatch, nlme, gdata, caret, rmarkdown, parallel