What is JetBrains for?
JetBrains specialises in intelligent, productivity-enabling tools to help you write clean, quality code across . NET, Java, Ruby, Python, PHP, JavaScript, C# and C++ platforms throughout all stages of development.

JetBrains supports non-commercial open-source projects by providing core project contributors with a set of best-in-class developer tools free of charge. More details you can find on this link.