Stu Bailey said the following in an interview published at sdncentral.com:
Open vSwitch is very Linux specific. And by the way, it was not originally created for OpenFlow; rather, it was created for virtual networking, and OpenFlow support was added later.
Both of these claims are wrong. First, Open vSwitch is not “very Linux specific.” It is primarily written against the standard POSIX API. This can be seen by the minimal amount of new code in the Open vSwitch port to FreeBSD, recently contributed by FreeBSD developers. The port required adding BSD implementations to network device and routing table support, since POSIX doesn't specify those interfaces. It also required a few bug fixes (one or two were actually due to FreeBSD divergence from strict POSIX compliance!).
Second, Open vSwitch evolved from an OpenFlow implementation, not the other way around. Open vSwitch has had OpenFlow support from day one. Its other features have been added over time.
Update: sdncentral posted a correction:
Ben, we spoke with Stu today about this and he defers to your points on this. Those were his own opinions on evaluating Open vSwitch. He wants to add that he is a huge fan of Open vSwitch. With Stu's permissions, we have made the appropriate modifications to the interview and the statements above have been stricken. Thanks for pointing those out!