Syntax highlighting. Look up documentation at callsite. Jump to definition. Run a test from the editor. Debug executables from within the editor. Fuzzy find file by name (for instance, typing "pluginfancymixi" should turn up something at "project/Plugins/third_party/username/project_name/fancy_mixin.language"). Third-party plugin support. Ability to have per-repo configurations
* Searching code:
Should be faster than grepping a bunch of directories. Supports wildcard searching. Bonus: tooling support for finding identifiers, callsites, usages, etc
* Development environment:
Any executable or test can run in one step (zero if possible). If possible, should be able to run multiple instances of your app at once. For example, I should be able to leave a webserver running so that my code reviewer can test it without pulling the branch
* Team environment:
Small PRs. Quick reviews. Tuned balance between senior and junior engineers. Should have enough senior engineers that they don't feel overwhelmed by the mentorship+training part of their job.
Edited: formatting