Well... I don't know that they ever officially released a protocol spec, but libpurple implements ICQ so at least enough of the protocol was reverse engineered or understood somehow to allow for OSS clients. So I suppose somebody could start from there and build a compatible server. Of course it might wind up only being compatible with Pidgin and other libpurple based clients, and the market for this is probably appr…
I contacted the company, suggested they bridged it to other protocols, and pointed them at FOSS code that would let them do it. I got a snarky email back saying that what I proposed was impossible -- even though others had done it before. Idiots.
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