The source base of Asmeta (including the documentation and the web site) is maintained in a Subversion repository at SourceForge. The repository's URL is
https://asmeta.svn.sourceforge.net/svnroot/asmeta/
You might also browse the Subversion repository online.
Repository Organisation
The file
http://asmeta.svn.sourceforge.net/viewvc/asmeta/readme.txt?view=markup
describes the organization of the repository.