Coincidentally, that would put the span between the final version's release and going on-sale at 16 days, the same number as for Snow Leopard.

Customers running Snow Leopard or Lion can upgrade to the new edition, which will be , a 33% discount compared to 2011's Lion.

Users concerned about application compatibility can , which lists the Mac programs that work with Mountain Lion's earlier builds, those that don't and the ones that balk in some way.

Applications that have been tested typically include users' comments that provide additional information on what worked and what didn't on Mountain Lion.

Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at , on or subscribe to . His email address is .