Packagist is the main Composer repository. It aggregates public PHP packages installable with Composer.
Useful array methods in PHP
Decorates a callback with cache (OPCache, FS) with LOCK_EX on write
Variable size symmetric key encryption algorithm
An extremely fast web scraper that parses megabytes of HTML in a blink of an eye. No dependencies. PHP5+
HTTP (<2.0) Requests over Socket - get as close to the socket level as possible
Peer to Peer Entropy Generator (or Random numbers generator with p2p seeding)
SipHash PHP implementation (-2-4 so far)