From here you can download the tools required for the GF-based functionality in KeY: translating OCL to natural language, and syntax editing of OCL and natural language in parallell.
Currently, you need three external binaries installed in your $PATH (or in $KEY_LIB) : gf, umltypes2gf, and ocl2nl. We provide statically linked linux binaries below, as well as a source distribution which should be easy to compile provided you have a recent version of the GHC Haskell compiler installed.
Check the troubleshooting page for a list of common problems.
Download, unpack (tar + bzip2) and install the three binaries somewhere in your $PATH
Download archive with Haskell source here: OCLNL-HSdist-060803.tar.bz2
Compile and install as follows (should work on Linux and Mac OS X):
Make sure that you have a recent version of the GHC Haskell compiler installed.
Unpack (tar + bzip2) the archive and cd into the directory OCLNL-HSdist.
Compile everything with the command make key-tools (this will take quite a while).
We also provide a tar archive of the OCLNL darcs repository, which contains the OCLNL GF grammar and the Haskell sources. (Note: you do not need darcs to use this archive.)