Some useful classes that I use a lot in my PHP projects.
Cache objects into disk or memcache\d.
File backend.
Memcache backend.
Memcached backend.
Factory to read some formats of configuration.
Read JSON files.
Read PHP files.
Encrypts and decrypts plaintext with a given key. Written to be compatible with it's counterpart in js. It use AES. Uses the slowAES encryption lib, which is more than fast enough for our purposes; using it here because it has several parallel versions in different languages (mainly php and js).
mysql_* functions wrapper.
mysqli_* functions wrapper.
To filter inputs.
HTML form creation and validation.
HMAC implementation.
To send emails as html or plain text.
Array utilities.
Text utilities.
Convert videos with mobile support, or any other format with ffmpeg.
Download videos from YouTube, Vimeo or any other embed URL.
A widgets factory.