For UTF-8 support in Win9x and WinME, R needs a Unicode support layer. Microsoft released MSLU in 2001; see these pages for details: http://www.microsoft.com/globaldev/handson/dev/mslu_announce.mspx http://msdn.microsoft.com/msdnmag/nettop.asp?page=/msdnmag/issues/01/10/MSLU/MSLU.asp&ad=ads.ddj.com/msdnmag/premium.htm Unfortunately, the license for MSLU is incompatible with the GPL under which R is released, so R is distributed with the Opencow library instead. See http://opencow.sourceforge.net We use the statically linked library libunicows to import the Unicode functions from opencows.dll (or from MSLU's unicows.dll, if it is present). See http://libunicows.sourceforge.net INSTALLATION Obtain a current binary version of opencow.dll from http://opencow.sourceforge.net or from http://www.murdoch-sutherland.com/Rtools. Obtain a current binary version of libunicows from http://libunicows.sourceforge.net or from http://www.murdoch-sutherland.com/Rtools. Install opencow.dll in this directory (src/gnuwin32/unicode), and install libunicows.a in the lib directory of your MinGW installation. Define the variable SUPPORT_UTF8 in src/gnuwin32/MkRules, and build R. LIMITATIONS This library allows Unicode executables to run, but it doesn't provide full Unicode support. In particular: [to be filled in]