Apache TripleSoup is an effort started within the Apache Incubator to create a SPARQL endpoint that is easy to set up, fast, maintainable, and such and so forth. We're only just getting started...
In the meantime, read the project proposal to get an idea of where we want to go.
(this blurb is here because of incubator policy)
Incubation is required of all newly accepted projects until a further review indicates that the infrastructure, communications, and decision making process have stabilized in a manner consistent with other successful ASF projects.
While incubation status is not necessarily a reflection of the completeness or stability of the code, it does indicate that the project has yet to be fully endorsed by the ASF.