APD is a general purpose non-interactive PHP profiler/debugger that produces formatted strace/truss type reports. APD supports full stack backtraces via calls similar to croak() in Perl's carp. APD is a Zend Extension and is designed to provide timing with the minimal performance impact. APD supports varying levels of debugging and can be turned on/off in individual scripts.
PEAR HTML_Template_IT provides two APIs to work with templates, a simple template API and an extended version. It supports blocks (including nested blocks), external file inclusion, and a custom tags format. With ITX, it is possible to modify blocks, replace or add blocks from files, and use callback functions.