PHP is very popular server-side programming language, that being used mostly for web-development. It is tied for a use with an http-server, think of Rack or WSGI, but built-in.

PHP characteristics:

• No official updated specification or a standard
• Weakly typed
• Optional types with runtime checks
• Garbage Collected
• Procedural, but community has a strong bias towards "traditional" Java OOP
• Java-like autoloaded classes (but done by 3rd party software called composer)
• OOP support, but not in a standard library
• Standard library functions are mostly written in C
• Extended by PHP extensions written in C
• More static than dynamic
• JIT Compilation, it is mostly faster than Python and Ruby
• Documentation is available in many languages including Russian
• Introspection is not great, but var_dump function is useful
• Node.js styled package manager (uses json & installs everything in project folder)
• Huge surface for different vulnerabilities
• Uses sigils just for variables, so they are kinda useless
• Even with OOP bias it doesn't support some OOP features:
  • You can set fields of an object outside of setter functions
  • You can't initialize some data types in fields, so you are forced to do that in constructor

You might have read the article called "PHP: a fractal of bad design". I want to note, that the language is indeed have a feel that it was built on top of poor fundament. Most of issues from that article are fixed now, but the language still falls under weight of legacy and bad initial design choices.

And yet it has good parts and that parts are important for business. That parts are:

• Support from a big company (Zend)
• Support of everything in C++ style The language even has goto statement
• C-like syntax, so many programmers can be quickly familiar with the language
• Java-like OOP, so programmers can enjoy reading Martin Fawler

Symfony is a web framework that wants to be Spring from java, but in php world. It uses OOP DDD patterns, Dependency Injection, DataMapper ORM. It is complex piece of software with good and quite detailed documentation.

• PHP is not controlled that much by a single company like Java controlled by Oracle.
• PHP is fast for scripting language compared to others, but not as fast as Java.
• Symfony provides backward compatibility promise.
• Symfony is not highly tighten, so it provides much more flexibility than monolith web frameworks like Django
• Many developers are available. The language has C syntax and types are optional.
• Existing ecosystem of packages. There are less things to develop from scratch (not that much packages compared to rails or django)

• PHP has single implementation and no standard which means that you probably will have to leave if implementators do something wrong with the only php interpreter. There are other implementation, but without a standard it is harder to switch between them (See how it is done in Common Lisp).
• PHP licensing is a bit complext (LWN). You can't patch PHP without changing its name. Devs have dropped GPL license.
• PHP has extension system which mostly compiled C code. I think many people don't read C code, so projects like Racket, Emacs or SBCL try to minimize C part of implementation.
• PHP doesn't allow monkey patching by default. You can't redefine standard library at all. No advices from Common Lisp / Elisp world.
• PHP tooling is mostly proprietary. It lacks proper emacs/vim support. Libre LSP servers are unmainteined or too laggy. Most people just use PHPStorm which is proprietary software or proprietary LSP server.
• Packagist contains non-free packages.
• Packagist doesn't store packages, it just contains links to git repositories. Haven't checked, but there is a possibility, that packages can be replaced by git push –force.
• Since C standard library is written in C it is hard to reimplement and fix code. It doesn't violate freedom of modification since you can fix your issues in C code, but it makes restrictions in emacs thesis sense where you can redifine everything in available system. It is applicatable to other programming languages too.
• Same goes to OOP. Property modificators make restrictions to user to modificate some parts of a program even if it is a broken part. There is Reflection API for fixing such issues or you can inherit broken class to a fixed class, but you can't really redefine some properties and methods.
• Symfony uses Stack Overflow instead of mailing lists. Stackoverflow needs auth, it is proprietary on server side and it uses proprietary javascript on client side.
• Symfony uses Slack instead of IRC/XMPP. Slack is corporate messaging solution, it is proprietary at server side and it uses proprietary javascript on client side. It is unusable with javascript disabled or with LibreJS extension.
• Composer and Symfony show ads while installing packages.
• Symfony has tons of ads on their documentation page. Symfony is promoting their proprietary services in docs pages. There is no documentation in info/man format without additional ads.
• Symfony requires some javascript to develop it and in some cases to use it as a visitor of your website.

• Remove ads from Symfony docs and host it elsewhere
• Remove ads from Symfony docs and make it available in info/man formats
• Do the same for PHP documentation website. HTML docs are not cool at all.
• Create licenses file for LibreJS
• Remove all ads from package manager
• Remove all proprietary services in symfony cli binary
• Create mailing lists, because stack overflow requires non-free javascript to read. SO is impossible to use offline.
• Create IRC <> Slack bridge or just irc room. Slack is proprietary and unaccessible by many people.

• GNU Social v2

Overall PHP and Symfony is not bad choice for libre development, but I would recommend to stick with python if it is available. PHP is better than Java in a sense, that it has much less corporate proprietary influence. I see corporate influence also in Ruby ecosystem where almost every package has sponsors by large companies, Python is much more clear in that regard.