PHP4 is discontinued since the end of the last year, read here. Due to that we developer won't continue to make certain that bebot will run under PHP4 anymore from the next version on.

What does this mean exactly? Up to now whenever we wrote a module we made sure that the functions used were supported by PHP4 too. This checking won't happen anymore, we will use PHP 5.2 as base for the function requirements. Most parts of the bot should still work under PHP4, we just won't guarantee or actively support backward compatibility anymore.

EDIT:
BeBot 0.6 will require PHP 5.2 to run, it won't run on PHP4 anymore. BeBot 0.6 will be the next stable release based on the trunk version, though there is no timeframe for it yet.
Any further BeBot 0.4 releases will most likely still run with PHP4. BeBot 0.4 is the current stable branch.

Added a paragraph about the current trunk version.