LTI from Moodle with automatic account creation, and UTF-8 support so Hebrew student names work.
Grade passback (homework) was tested successfully, but is not in active use.
We have been using the code which is now in the WW 2.15 branch (essentially a release candidate) for about 6 months. Sites which had issues when student names have special characters are encouraged to migrate to WW 2.15. (shameless plug) now or after the formal release.