I don't know about Mac support, but jackrabbit  is only the reference implementation for JCR (JSR 170)
it means at best it is only a repository not a complete DMS,CMS or WCMS like Slide.
you have to build your system on the repository.
jackrabbit is very slow compared to some commercial counterparts like Day or Oracle.
if you want high performance implementation try other implementations.

As far as I Know ,Day CRX is a packaged version of Apache Jackrabbit . Do you think it has better performance than Jackrabbit?

it is more than a year that I haven't used jackrabbit, at that time there was a component named "Persistence Manager" responsible for mapping nodes and it was just a simple one, not much optimized, now there are more Persistence Managers developed and they may be as fast as CRX and other commercial implementations.

Alfresco has developed a test suite for JCR implementations, you can run the test suit against different JCR implementations and pick you choice try the followings:

1- Alfresco
2- Oracle
3- EXO
4- CRX