IntelliJ IDEA is second most popular IDE for JVM (have 44% share, after Eclipse 48%). Also it's popular on other platforms and have special versions for developers on Python, PHP, Ruby and C/C++. Many of ETC Dapp developers are using this IDE.
But currently it doesn't have a plugin for Solidity, check there https://plugins.jetbrains.com/search/index?search=solidity
I think it's important to create a basic plugin, for a minimal version it will be enough to have:
- syntax coloring for Solidity language
- calling an external Solc and getting ABI and bytecode for a file
ETC community & Dapp developers will appreciate if anyone will start this plugin. There're many open source examples of similar plugins. This is for Dart, for example: https://github.com/JetBrains/intellij-plugins/tree/master/Dart