...(since about version 3 I think) and I'm very happy with it. For the record: ClearOS *IS* Clark Connect, it just grew up.
And also for the record, it may based on OSS software, but it's not *purely* free / user supported. Clear's business model is similar to Ubuntu's, i.e. the basic package is free to download and free to use, but there is a choice of paid-for services that you can add to it a la carte style. These give you back-end services and a service level to suit your business (still cheaper than going the M$ route, if you are a small business), or you can stick with the free version which is good enough for most companies I work with. Technical support in this model is via a community forum only, but you often find developers lurking and helping out there.
It's a robust and well thought out package that I find more stable in certain applications - e.g. VPN termination - than some of the alternatives (WinXP the notable example). And the biggest bonus is that it will happily run on old hardware that is no longer acceptable as a Windows workstation (speaking for myself, running the Clear box as a gateway / firewall and file / printer sharer only) - for instance, a P4 with 20 GB disc and 512 MB of RAM is pretty much useless for running anything more than Win98, yet COS is ecstatic about all that free space and memory and runs like a dream. Most companies have at least one or two of that sort of computer lying around that no-one wants to throw away - so they can afford to keep a second machine on standby in case of hardware failure, and with regular backups the swap-out can be almost as simple as replacing a DSL modem. Really.
All is not completely perfect: Clear's reporting still needs work. Troubleshooting an issue can be quite frustrating if you don't know how Linux reports work (particularly filtering events - never did get the hang of regular expressions). The MRTG-based reports are great, if all you want to look at is graphs of system load or netwrok throughput, but trying to work out why Steve in Cincinatti can't remote connect to the database can take a while.
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