WordPress.org

What is the minimum PHP requirement?

For the plugin itself, PHP4 is enough. But, PHPingFm class needed PHP5 to run properly. Conclusion? PHP5!

Why don't you use / create a library that support PHP4

Why should I reinvent the whell? It's you or your hosting server that needed an upgrade. PHP4 is dead, move along.

I can post to WP without problems but I am not seeing the update come into Pingfm?

First, make sure you fill in the correct Application Key. Then, set the mode to: For all categories (all)

I still don't see any update come to Pingfm

Maybe there's something wrong with your server configurations. Note: You need PHP5 and CURL library to make it working properly.