I've posted source tarballs/zips for KOS 1.1.1, and also pre-compiled binary images for DC only. If you only want to develop software using KOS, then you probably want to grab the binary release since it's much simpler to work with. Otherwise, you can grab the source and tinker with it. For some reason it's not showing any files under the file listing, but hopefully this will mysteriously correct itself like most SourceForge problems.
For now you will need to look to the main project home page for news items. The official URL to the home page is "http://dcdev.allusion.net/".