Mod_lsapi is the fastest and most reliable way to serve PHP pages. It is a drop-in replacement for SuPHP, FCGID, RUID2, and ITK. It has a low memory footprint and understands PHP directives from .htaccess files. Mod_Isapi:
Is faster than any other way to serve PHP with Apache.
Doesn't suffer from stability issues in process management like PHP FPM and mod_fcgid.
Includes the full benefits of opcode caching.
Is compatible with MPM Worker and Event.
Does not require tuning.
Includes support for PHP directives in .htaccess files.
Is a drop-in replacement for existing ways to serve PHP.
Is fully compatible with PHP Selector.