All versions of jhc are available from the Download Directory. The project is also under darcs revision control, for information on getting the source code from darcs and building it, see the Development Page.
This is by far the easiest way to go about it, an RPM for x86 based systems (32 or 64 bits) can be instaled from: http://repetae.net/computer/jhc/drop/jhc-0.5.20080307-1.i386.rpm. There is also a 'src' rpm in the download directory for rebuilding from source.
jhc is also distributed via a autoconf/automake style tarball. Building jhc has the following dependencies:
You can get the tarball at http://repetae.net/computer/jhc/drop/jhc-0.5.20080307.tar.gz. In order to build it, download it into a directory and perform the following
tar zxvf jhc-0.5.20080307.tar.gz
cd jhc-0.5.20080307
./configure && make
then as root run
make install
All these prepackaged versions of jhc come with prebuilt versions of the 'base' and 'haskell98' libraries for use by jhc in addition to the sourcecode for these libraries. You can rebuild them if you wish simply by deleting the '.hl' files in your build directory and doing a 'make libs'. however it is recommended you work with the development darcs tree if you plan on modifying the base libraries.