I can see that GD library is for images. But I can't see differences between PECL and PEAR. Both have authentication. What are the main differences between two? Why don't they combine them?
6 Answers
From my understanding, PHP has modules and frameworks, both being its libraries, external modules, called extensions, live in its PECL repository, while frameworks, called packages, live in its PEAR repository.
One can use PEAR packages within PHP code by simply sourcing the source code files, but PECL extensions should be installed on the system and enabled in configuration files to link to the interpreter.
Also, PEAR packages are written in PHP and are plain-text scripts, while PECL extensions are written in C/C++ and are compiled binaries in their consummable form.
Extensions as the name suggest extend PHP with something it doesn't offer by itself yet, while packages are just a collection of PHP code, ie. everything you can do with PHP proper.
This is parallel to Perl's PM modules and XS extensions.
That said, my view may not be 100% accurate, but that's how I could settle this in my mind :-)
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