Many companies have reservations about using open-source software, preferring instead to use commercially-supported products.

Companies who have used open-source software tend to use it because:

• It’s often cutting-edge, created by developers who needed it for their own projects
• If any bugs are found, they can be quickly patched; this patch can then be contributed to the project maintainers
• It’s easier to pin down the source of any bugs, since the source code is available
• Commercial software can be buggy too, and updates can be slow in coming
• It’s free!

I’m a lead developer on the open-source projects mentioned here.