Which engine to choose for a collaborative blog/news site?

Question

CMS

Please advise an engine (similar to a group in a social network), which additionally implements the following functions:
1) access by invitations
2) accounting for invitees and invitees as on trackers
3) authorization via Facebook
4) differentiation of rights to write / post news

Answer 1

All this goodness can be collected on wordpress, plug-ins wagon and a small cart. Well, or modx, if you fumble a little in layout and php)