You can compile Kawa from the source distribution. Alternatively, you can install the pre-compiled binary distribution.
You can get Kawa sources and binaries from the Kawa ftp site ftp://ftp.gnu.org/pub/gnu/kawa/, or from a mirror site.
The latest release of the Kawa source code is
ftp://ftp.gnu.org/pub/gnu/kawa/kawa-2.1.tar.gz.
(To unpack .tar.gz files Windows users can use
7-Zip, which is Free Software.)
A ready-to-run .jar archive of the pre-compiled classes is in
ftp://ftp.gnu.org/pub/gnu/kawa/kawa-2.1.jar.
The Kawa sources are managed using a Subversion (svn) repository. If you want the very latest version grab an svn client, and then check out the source using this command:
svn -q checkout svn://sourceware.org/svn/kawa/trunk kawa
Some corporate firewalls may block outgoing Subversion
connections. If that case you should be able to access the
Kawa Subversion repository using HTTP. (If you need
to use an HTTP proxy, you can edit
http-proxy-host and http-proxy-port
in ~/.subversion/servers as described
here.)
Use this command instead:
svn -q checkout http://sourceware.org/svn/kawa/trunk kawa
Once you have it checked out, you can keep it up-to-date with svn update.
You can also browse the svn archive via viewvc.