…ey're in the system hive in the registry, so only people with administrative priveleges can add stuff in there.
LZW patent violation so we can distribute read-only GIF support with our bundled GD2. The patent also expires in 2003, which is quickly approaching, so we can roll in write support soon unless things change.
…ining a directory which will be scanned for *.ini files after the main php.ini file has been parsed. This makes it much easier to automatically deploy a modular PHP since adding extensions which have their own ini switches can now be done by simply dropping a foo.ini file in the right directory and restarting. A list of parsed ini files is maintained and shown on the phpinfo page.