We often get asked this question linu. Some suggestions:
- Fix marginalia for Moodle 3.4. http://webmarginalia.net/
- Take an existing module and enhance it to improve collaboiration
- Inline editing for forums https://tracker.moodle.org/browse/MDL-33692 This will immediatley raise the level of forum replies since you can see what you are actually replying to at a thread level.
- Improve collaborative file sharing. eg List all attached files in a forum. https://tracker.moodle.org/browse/MDL-27062
Just three ideas!!