diff --git a/.gitignore b/.gitignore
new file mode 100644
index 00000000..d4eb940a
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+.DS_Store
+tmp
diff --git a/bin/run_tests.R b/bin/run_tests.R
new file mode 100755
index 00000000..59f987b3
--- /dev/null
+++ b/bin/run_tests.R
@@ -0,0 +1,29 @@
+#!/usr/bin/env Rscript
+# run_tests -- run R tests for exercism.io
+# the following were useful in writing this script:
+#   http://mazamascience.com/WorkingWithData/?p=888 for writing command line scripts
+#   http://www.johnmyleswhite.com/notebook/2010/08/17/unit-testing-in-r-the-bare-minimum/ for using RUnit
+
+
+# function to determine if a package is installed
+# will install it if necessary and load it
+# otherwise stops the script with an error message
+# source: http://stackoverflow.com/q/9341635
+install.if.necessary <- function(package.name) {
+  if ( !require(package.name, character.only=TRUE) ) {
+    install.packages(package.name, repos="http://cran.cnr.Berkeley.edu/")
+    if ( !require(package.name, character.only=TRUE) ) stop( paste( package.name, " not found") )
+  }
+}
+
+# make sure RUnit is installed and loaded
+install.if.necessary("RUnit")
+
+# define a test suite; looks for files named "^.*_test.R" in current directory 
+test.suite <- defineTestSuite("exercism", dirs = getwd(), testFileRegex = "^.*_test\\.R" )
+
+# run the tests
+test.result <- runTestSuite(test.suite)
+
+# output the result
+printTextProtocol(test.result)
\ No newline at end of file
diff --git a/bin/run_tests.bat b/bin/run_tests.bat
new file mode 100644
index 00000000..6327f21a
--- /dev/null
+++ b/bin/run_tests.bat
@@ -0,0 +1,12 @@
+@echo OFF
+
+REM The location of the registry key for the current version of R
+set R_PATH_KEY=HKLM\Software\R-core\R
+set R_PATH_VAL=InstallPath
+
+REM Get the path where R is installed
+set R_PATH=
+for /f "tokens=2,*" %%a in ('reg query %R_PATH_KEY% /v %R_PATH_VAL% ^| findstr %R_PATH_VAL%') do (set R_PATH=%%b)
+
+REM Run run_tests.R
+Rscript "%R_PATH%"\bin\run_tests.R
\ No newline at end of file
diff --git a/config.json b/config.json
index ef79bff9..36a75bd0 100644
--- a/config.json
+++ b/config.json
@@ -1,18 +1,17 @@
 {
   "slug": "r",
   "language": "R",
-  "repository": "https://github.com/exercism/xr",
-  "active": false,
+  "repository": "https://github.com/morphatic/xr",
+  "active": true,
   "problems": [
-
+    "hello-world",
+    "hello-variables",
+    "operate"
   ],
   "deprecated": [
-
   ],
   "ignored": [
-
   ],
   "foregone": [
-
   ]
 }
diff --git a/hello-variables/example.R b/hello-variables/example.R
new file mode 100644
index 00000000..b3bb3145
--- /dev/null
+++ b/hello-variables/example.R
@@ -0,0 +1,3 @@
+say.hello.to <- function(name) {
+  return(paste("Hello, ", name, "!", sep=""))
+}
\ No newline at end of file
diff --git a/hello-variables/hello-variables_test.R b/hello-variables/hello-variables_test.R
new file mode 100644
index 00000000..15b2f4ee
--- /dev/null
+++ b/hello-variables/hello-variables_test.R
@@ -0,0 +1,14 @@
+test.hello.variables <- function() {
+  
+  # default filename is example.R
+  filename <- "example.R"
+  
+  # check for hello-world.R
+  if (file.exists("hello-variables.R")) filename <- "hello-variables.R"
+  
+  # load the code to be tested
+  source(filename)
+  
+  # test the output
+  checkEquals(say.hello.to("Bob"), "Hello, Bob!")
+}
\ No newline at end of file
diff --git a/hello-world/example.R b/hello-world/example.R
new file mode 100644
index 00000000..eddc2723
--- /dev/null
+++ b/hello-world/example.R
@@ -0,0 +1,3 @@
+say.hello <- function() {
+  return("Hello, World!")
+}
\ No newline at end of file
diff --git a/hello-world/hello-world_test.R b/hello-world/hello-world_test.R
new file mode 100644
index 00000000..736509ec
--- /dev/null
+++ b/hello-world/hello-world_test.R
@@ -0,0 +1,14 @@
+test.hello.world <- function() {
+  
+  # default filename is example.R
+  filename <- "example.R"
+  
+  # check for hello-world.R
+  if (file.exists("hello-world.R")) filename <- "hello-world.R"
+  
+  # load the code to be tested
+  source(filename)
+  
+  # test the output
+  checkEquals(say.hello(), "Hello, World!")
+}
\ No newline at end of file
diff --git a/operate/example.R b/operate/example.R
new file mode 100644
index 00000000..0d5dff3d
--- /dev/null
+++ b/operate/example.R
@@ -0,0 +1,22 @@
+# Arithmetic Operators
+add       <- function( a, b ) { return( a  + b ) }
+subtract  <- function( a, b ) { return( a  - b ) }
+multiply  <- function( a, b ) { return( a  * b ) }
+divide    <- function( a, b ) { return( a  / b ) }
+remainder <- function( a, b ) { return( a %% b ) }
+
+# Comparison Operators
+equals         <- function( a, b ) { return( a == b ) }
+isIdentical    <- function( a, b ) { return( identical( a, b ) ) }
+notEquals      <- function( a, b ) { return( a != b ) }
+notIdentical   <- function( a, b ) { return( ! identical( a, b ) ) }
+lessThan       <- function( a, b ) { return( a <  b ) }
+lessOrEqual    <- function( a, b ) { return( a <= b ) }
+greaterThan    <- function( a, b ) { return( a >  b ) }
+greaterOrEqual <- function( a, b ) { return( a >= b ) }
+
+# Logical Operators
+logicalAnd <- function( a, b ) { return( a & b ) }
+logicalOr  <- function( a, b ) { return( a | b ) }
+logicalXor <- function( a, b ) { return( ( a & !b ) | ( !a & b ) ) }
+logicalNot <- function( a    ) { return( ! a   ) }
diff --git a/operate/operate_test.R b/operate/operate_test.R
new file mode 100644
index 00000000..cb53396e
--- /dev/null
+++ b/operate/operate_test.R
@@ -0,0 +1,105 @@
+test.hello.world <- function() {
+  
+  # default filename is example.R
+  filename <- "example.R"
+  
+  # check for hello-world.R
+  if (file.exists("operate.R")) filename <- "operate.R"
+  
+  # load the code to be tested
+  source(filename)
+  
+  # test Arithmetic Operators
+  checkEquals( add(   2,   2 ),   4 )
+  checkEquals( add(   7,   3 ),  10 )
+  checkEquals( add( 123, 456 ), 579 )
+
+  checkEquals( subtract(   2,   2 ),    0 )
+  checkEquals( subtract(   7,   3 ),    4 )
+  checkEquals( subtract( 123, 456 ), -333 )
+
+  checkEquals( multiply(   2,   2 ),     4 )
+  checkEquals( multiply(   7,   3 ),    21 )
+  checkEquals( multiply( 123, 456 ), 56088 )
+
+  checkEquals( divide(   2,   2 ),       1 )
+  checkEquals( divide(   7,   3 ),     7/3 )
+  checkEquals( divide( 123, 456 ), 123/456 )
+
+  checkEquals( remainder(   2,   2 ),   0 )
+  checkEquals( remainder(   7,   3 ),   1 )
+  checkEquals( remainder( 123, 456 ), 123 )
+  
+  # test Comparison Operators
+  checkTrue(   equals(    3 ,      3  ) )
+  checkTrue(   equals(    3 ,     '3' ) )
+  checkTrue(   equals( 'Bob',   'Bob' ) )
+  checkTrue( ! equals(    3 ,      4  ) )
+  checkTrue( ! equals(    3 , 'three' ) )
+
+  checkTrue(   isIdentical(    3 ,      3  ) )
+  checkTrue( ! isIdentical(    3 ,     '3' ) )
+  checkTrue(   isIdentical( 'Bob',   'Bob' ) )
+  checkTrue( ! isIdentical(    3 ,      4  ) )
+  checkTrue( ! isIdentical(    3 , 'three' ) )
+
+  checkTrue( ! notEquals(    3 ,      3  ) )
+  checkTrue( ! notEquals(    3 ,     '3' ) )
+  checkTrue( ! notEquals( 'Bob',   'Bob' ) )
+  checkTrue(   notEquals(    3 ,      4  ) )
+  checkTrue(   notEquals(    3 , 'three' ) )
+
+  checkTrue( ! notIdentical(    3 ,      3  ) )
+  checkTrue(   notIdentical(    3 ,     '3' ) )
+  checkTrue( ! notIdentical( 'Bob',   'Bob' ) )
+  checkTrue(   notIdentical(    3 ,      4  ) )
+  checkTrue(   notIdentical(    3 , 'three' ) )
+  
+  checkTrue( ! lessThan(  3 ,  3  ) )
+  checkTrue(   lessThan(  3 ,  4  ) )
+  checkTrue( ! lessThan(  4 ,  3  ) )
+  checkTrue( ! lessThan( 'a', 'a' ) )
+  checkTrue(   lessThan( 'a', 'b' ) )
+  checkTrue( ! lessThan( 'b', 'a' ) )
+
+  checkTrue(   lessOrEqual(  3 ,  3  ) )
+  checkTrue(   lessOrEqual(  3 ,  4  ) )
+  checkTrue( ! lessOrEqual(  4 ,  3  ) )
+  checkTrue(   lessOrEqual( 'a', 'a' ) )
+  checkTrue(   lessOrEqual( 'a', 'b' ) )
+  checkTrue( ! lessOrEqual( 'b', 'a' ) )
+
+  checkTrue( ! greaterThan(  3 ,  3  ) )
+  checkTrue( ! greaterThan(  3 ,  4  ) )
+  checkTrue(   greaterThan(  4 ,  3  ) )
+  checkTrue( ! greaterThan( 'a', 'a' ) )
+  checkTrue( ! greaterThan( 'a', 'b' ) )
+  checkTrue(   greaterThan( 'b', 'a' ) )
+
+  checkTrue(   greaterOrEqual(  3 ,  3  ) )
+  checkTrue( ! greaterOrEqual(  3 ,  4  ) )
+  checkTrue(   greaterOrEqual(  4 ,  3  ) )
+  checkTrue(   greaterOrEqual( 'a', 'a' ) )
+  checkTrue( ! greaterOrEqual( 'a', 'b' ) )
+  checkTrue(   greaterOrEqual( 'b', 'a' ) )
+  
+  # test Logical Operators
+  checkTrue(   logicalAnd(  TRUE,  TRUE ) )
+  checkTrue( ! logicalAnd(  TRUE, FALSE ) )
+  checkTrue( ! logicalAnd( FALSE,  TRUE ) )
+  checkTrue( ! logicalAnd( FALSE, FALSE ) )
+
+  checkTrue(   logicalOr(  TRUE,  TRUE ) )
+  checkTrue(   logicalOr(  TRUE, FALSE ) )
+  checkTrue(   logicalOr( FALSE,  TRUE ) )
+  checkTrue( ! logicalOr( FALSE, FALSE ) )
+
+  checkTrue( ! logicalXor(  TRUE,  TRUE ) )
+  checkTrue(   logicalXor(  TRUE, FALSE ) )
+  checkTrue(   logicalXor( FALSE,  TRUE ) )
+  checkTrue( ! logicalXor( FALSE, FALSE ) )
+
+  checkTrue( ! logicalNot(  TRUE ) )
+  checkTrue(   logicalNot( FALSE ) )
+
+}
\ No newline at end of file