As of late last night, you can now download (no SVN required) a tarball of a fully-operational Solar system with the 1.0.0alpha2 code in place.
Extract the tarball directly in your document root.
Make the "tmp" and "sqlite" directories writable by the web server process; e.g.,
chmod -R 777 tmp/ sqlite/.
Browse to the "hello" and "bookmarks" apps to watch it work.
After that you can start changing configs, adding your own libraries, and building your own applications.
For a bit more info, see the Download page.