Toby Kurien: "If the GemThread server goes down, all I am left with are my responses with possibly no link-back to the original thread nor a way to rebuild the thread by following and collecting links. Seems like a centralization problem."
This is also a concern I share. This calls for some sort of mirroring, archive protocol, or federation. More thought is required. :)
Toby's suggestion: "Perhaps it's the responses that should link back to the topic, and up to GemThread to pull them all together like the lace script currently does. So a poster can just submit their response to GemThread and it finds the original topic, creates it if necessary, and stitches in the response."
This feels like an easier way to initiate a thread.
Also an archiving suggestion (also from Toby): "A more radical idea is that each thread is compiled into a gempub. To view a thread and the responses, you download the latest gempub and view it. When a user adds another response, the gempub is recompiled with the new response inlined. This way, if the GemThread server is taken offline, people may still have gempub copies of the threads they were interested in. Perhaps this could be extended with an aggregator that downloads gempubs for thread you've started or responded to."
This would be relatively trivial to add.