A wiki dedicated to Model-based Systems Engineering (MBSE) topics, including SysML modeling. The MBSE Wiki purports to support the INCOSE MBSE initiative and the OMG Systems Engineering Domain Special Interest Group.
A web community dedicated to the Unified Modeling Language (UML), the parent language from which SysML was derived. (SysML is a Profile or dialect of UML 2.x.) Here you can find information related to UML specifications, UML tools, UML training, UML tutorials, UML publications, and UML discussion groups.