Mac OS X Snow Leo­pard was released by Apple on August 28, 2009. Fam­ous for being announced as hav­ing “no new fea­tures”, that’s not entirely the case. This sev­enth major ver­sion of Mac OS X was designed to improve per­form­ance and effi­ciency, reduce memory usage, and increase HDD space. As Snow Leo­pard is also the first Mac oper­at­ing sys­tem since Sys­tem 7 to not sup­port PPC archi­tec­ture, there is under­stand­ably a lot of ques­tions about com­pat­ib­il­ity, require­ments, speed, and other changes to be answered.

First up we have a Snow Leo­pard com­pa­t­ablity list, very use­ful for any­body that has not yet upgraded. Make sure to search through for all your import­ant applic­a­tions, but be aware that there are still many not on the list. About the only application/plugin that I use with any reg­u­lar­ity that is still not work­ing in Snow Leo­pard would be the Let­ter­box plu­gin for Mail that rearranges the win­dow into three ver­tical columns to take advant­age of widescreen mon­it­ors, but an update should be avail­able shortly.

If you’re want­ing some quick reviews of Snow Leo­pard, then Wired has a bunch. Start­ing with 6 Things You Need To Know About Snow Leo­pard, How Snow Leo­pard Will Improve Your Hard­ware, and a review. They also have a reas­on­ably detailed upgrade guide. And if you’re won­der­ing just what is miss­ing in Snow Leo­pard, then this link is for you.

How­ever, the cream of the crop of Snow Leo­pard reviews would have to be this 23 page review by John Siracusa of Ars Tech­nica. Make sure to set aside the couple of hours that you will need to read through it all, and if you’re at all inter­ested in the core tech­no­logy and changes beneath the skin then don’t skip through the middle. For the even more tech­nic­ally ori­ent­ated amongst you, we have an Apple Developer Cen­ter art­icle detail­ing What’s New in 10.6 for developers.

I’ve been using Snow Leo­pard for what is com­ing up on a couple of weeks now, and find it blaz­ingly fast when com­pared to 10.5, even on my 32bit Mac­Book Pro. Over­all, it’s well worth the £25 upgrade price.