https://www.whonix.org/wiki/I2P#RetroShare states the following:
The development of I2P’s distributed forum software (Syndie) is stalled indefinitely.
Is there a citation available for this? It looks like that statement was added on April 23, 2016: https://www.whonix.org/w/index.php?title=I2P&type=revision&diff=23281&oldid=22651 . There have been about 2.5 pages of GitHub commits to Syndie since that date: https://github.com/i2p/i2p.syndie/commits/master .