I can also suggest you to approach JetBrains people if you see them in at a conference. They sponsor many PHP conferences, and open source maintainers (don't have to Linus) can request or open-source license.
They also have an Early Access Program that you try out beta releases, and they are free of cost.
And if you are an individual, the license is just 89 USD.
If you are an individual contractor, then maybe you quality for a startup discount? This also gives you 50%: https://www.jetbrains.com/phpstorm/buy/#personal?billing=yea...