yes, you want to fork from 1.3wip if you want the 1.3 codebase. git clone git://github.com/mootools/mootools-more.git cd mootools-more git checkout -b 1.3wip origin/1.3wip
if you intend to push, you should fork on github and instead clone from your own repo. Is the plan to put out an 1.3 -more when 1.3 -core comes out? > Yes
