Microsoft has closed a patent cross-licensing deal with Samsung on April 19th.
Both Microsoft and Samsung are companies which are heavily armed with patents in the software area. Samsung is one of the major sellers of tech equipment, especially embedded devices. For quite some of their devices, they use Linux as an embedded operating system.
Microsoft however has its own embedded operating system called Windows CE. It is mainly a big, barely portable chunk of code which uses their famous microkernel approach in order to be able to load drivers for the hardware it runs on. However, Microsoft owns a couple of patents on several software techniques deployed also by Linux (so-called trivial patents). Based on these patents, many of which haven't seen an examination in court yet, Microsoft claims ownership of nothing other than the Linux operating system itself.
This approach is not new. Microsoft has recently convinced Novell to give in to a «extended partnership», which included a patent deal. In the course, Novell removed such useful things as laptop optimized font rendering from their Novell Linux (formerly SuSE Linux) distribution. The question remains whether this was actually in the interest of the customers.
As a side note, in terms of annual turnover, Microsoft and Samsung play about in the same league.