> openoffice isn't much legal in the us since MS Office is patented per se and one
> cannot "create similar software, having basically all the same features". So in the
> US, oo violates MS Office.

Little anecdote recently told by the former SUN CEO:

"As in life, bluster and threat are commonplace in business - especially the technology business. So that interaction was good preparation for a later meeting with Bill Gates and Steve Ballmer. They'd flown in over a weekend to meet with Scott McNealy, Sun's then CEO - who asked me and Greg Papadopoulos (Sun's CTO) to accompany him. As we sat down in our Menlo Park conference room, Bill skipped the small talk, and went straight to the point, "Microsoft owns the office productivity market, and our patents read all over OpenOffice." OpenOffice is a free office productivity suite found on tens of millions of desktops worldwide. It's a tremendous brand ambassador for its owner - it also limits the appeal of Microsoft Office to businesses and those forced to pirate it. Bill was delivering a slightly more sophisticated variant of the threat Steve had made, but he had a different solution in mind. "We're happy to get you under license." That was code for "We'll go away if you pay us a royalty for every download" - the digital version of a protection racket. Royalty bearing free software? Jumbo shrimp. (Oxymoron.) But fearing this was on the agenda, we were prepared for the meeting. Microsoft is no stranger to imitating successful products, then leveraging their distribution power to eliminate a competitive threat - from tablet computing to search engines, their inspiration is often obvious (I'm trying to like Bing, I really am). So when they created their web application platform, .NET, it was obvious their designers had been staring at Java - which was exactly my retort. "We've looked at .NET, and you're trampling all over a huge number of Java patents. So what will you pay us for every copy of Windows?" Bill explained the software business was all about building variable revenue streams from a fixed engineering cost base, so royalties didn't fit with their model... which is to say, it was a short meeting."
http://jonathanischwartz.wordpress.com/2010/03/09/good-artists-copy-great-artists-steal/