Yahoo was a leader in many areas - search, portal, messaging. But as they've aged, their engineering teams are beginning to suffer some of the same problems as the rest of us. Cutting-edge platforms (at one time), often of a proprietary nature, need a hard look and difficult, often expensive, choices need to be made about the continued use of those platforms.

A Yahoo insider comments on their dead-end infrastructure:

And let me tell you this. Yahoo! is now rotten from the inside out. Here's my take of how to fix Yahoo!'s engineering:

... 4) Slowly port all Yahoo! software to linux and phase out FreeBSD. Start supporting and encouraging multi-threading programming. I bet Google is laughing their asses off at us because we are still stuck with FreeBSD, gcc-2.95 and single process model.

...

5) Slowly get rid of all Yahoo-specialized open source software. Why do we have "YApache" (based on Apache 1.3), and why do we have the dreaded yut/ycore++ libraries when we can use STL and boost? And why do we have YPAN when we can just use CPAN??? The platform group is doing the wrong job supporting this dead-end infrastructure.