And what about 5.8.0? ;-)

It not only depends on what you your target audience is, but also on what you want to do. Threading was seriously broken on 5.005, it got better in 5.6, but in 5.8 we take huge leaps forward. It's the same when it comes to Unicode. If you want a crossplatform fork(), you need 5.6. There's much more 64bit support in 5.6 than 5.005. Large file support in in 5.6, not 5.005. And then there's a whole flock of smaller additions to 5.6.

Abigail