After loads of reports that the Melange site keeps going 505 and crashing, I took at look at why. Turns out several spam crawlers were going mental and repeatedly adding tickets with spam links. Around 600 tickets and thousands of comments later, the process decided it had enough and terminated.
I’ve deleted all tickets (even the valid ones were spammed into oblivion) and turned off comment creation and modification for anonymous users. A look on the Trac Wiki shows that there are some SpamFilter extensions being developed which I’ll investigate at some point.