Transport gateway alternatives

Are there any viable alternatives to Kraken? I have been using it in a production environment with about 2,000 users and it’s just a bit too flaky for prime time. It seems like the project only has one dev (Daniel), and he’s got a day job. Daniel recommends a commercial offering on his site. It’s some outfit in Europe. I don’t recall the name and the Kraken website is down right now. However, I sent them several emails and never got a reply.

If anyone has successfully implemented a gateway other than Kraken or its predecessor IM gateway plugin, I’d love to hear from you.