It's been a landmark year for open source, and in so many different ways that even a casual survey of the year's events will range far and wide.  Here's a quick rundown of what to me were the top five open source events of the year -- not an exhaustive list, of course, but the things that best reflected how important and widely entrenched open source software (especially Linux) has become.

1. Microsoft and the Samba Team. After a good deal of constant outside pressure, Microsoft has finally allowed the technical details of many of its proprietary protocols to be revealed, albeit in a controlled way.  The most important thing about this agreement is that it allows open source programmers to avoid certain Microsoft patents that might have made them the target of future litigation.  It's a step toward ending Microsoft's secretive Linux patent strategies once and for all.

2. The OLPC, the Eee PC, and the gPC.  No less than three personal-computing devices appeared this year, each in a slightly different niche, all of which ran a variety of Linux as their out-of-the-box operating system.  The OLPC was significant enough by itself -- both as an open-source event and as a way to bring computing to developing nations - but the Eee PC and gPC, marketed at many of us right here at home, were even bigger heralds for how much closer Linux is to being a household name.  Which leads us to ...

3. Dell shipping Ubuntu Linux with selected machines.  This was more than just Dell adding Ubuntu as a pre-load option, but certifying that Ubuntu would work with its machines, too.  As tentative as the whole thing was at first, it has since become a possible point of inspiration for other PC retailers (such as HP).  Whether or not Ubuntu will knock Windows out of the box is doubtful, but it at least means that much more choice -- and competition.

4. The GPLv3.  The most widely used open source software license around got a third revision this year, one which sparked a good deal of controversy both inside and outside the open source community.  Some saw it as a way for open source folks to engineer an end-run around Microsoft, and its growing patent-squeeze of Linux vendors.

5. The BusyBox / Verizon lawsuit.  Makers of a popular open source tool collection, BusyBox, are bringing suit against Verizon for offering the program as part of a broadband router but not offering the source code as well (as part of the license terms for the program).  If this goes to trial, rather than ending in a settlement, it would be a huge test of the GPL as an enforceable contract -- and it would be a test of the GPL in the context of its violation by a major, brand-name company (Verizon).  Note that it's entirely possible that the real culprit here is not Verizon but the makers of the router itself, Actiontec -- although it still remains to be seen if Verizon will attempt to pass the buck, settle, or decide to go to trial.