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 current release of the Kawa source code is
ftp://ftp.gnu.org/pub/gnu/kawa/kawa-3.1.1.tar.gz.
(To unpack .tar.gz files Windows users can use
7-Zip, which is Free Software.)
The corresponding pre-compiled release is ftp://ftp.gnu.org/pub/gnu/kawa/kawa-3.1.1.zip. The most recent snapshot is ftp://ftp.gnu.org/pub/gnu/kawa/kawa-latest.zip. Instructions for using either are here.
The Kawa sources are managed using a git repository. If you want the very latest version grab a git client, and then check out the source using this command:
git clone https://gitlab.com/kashell/Kawa.git
After a checkout you will need to run:
./autogen.sh
before proceding with instructions for building the source distribution.
Once you have it checked out, you can keep it up-to-date with git pull.
You can also browse the git archive online.
