According to the press release from SF about their OpenID support:

OpenID is getting tremendous traction and we're happy to be jumping into it. it's bringing us back in touch with fresh web (2.0) technology. [...] We've spent the past couple weeks on it - integrating the Zend Framework OpenID component into our site code. we like the framework as a whole and I personally hope to use more of it in the future.

There might be a few kinks in the process, so if you're seeing issues with your OpenID working on their site, check out the FAQ they've posted to help.

To put it simply, Krumo is a replacement for print_r() and var_dump(). By definition Krumo is a debugging tool (now for PHP5 only), which displays structured information about any PHP variable [...] it does the same job, but it presents the information beautified using CSS and DHTML.

It also supports output of other data in a "pretty format" like backtraces, included files and a listing of all constants. You can check out a demo of it in action here.