ccls, which originates from cquery, is a C/C++/Objective-C language server.

- code completion (with both signature help and snippets)
- definition/references, and other cross references
- cross reference extensions: $ccls/call $ccls/inheritance $ccls/member $ccls/vars ...
- formatting
- hierarchies: call (caller/callee) hierarchy, inheritance (base/derived) hierarchy, member hierarchy
- symbol rename
- document symbols and approximate search of workspace symbol
- hover information
- diagnostics and code actions (clang FixIts)
- semantic highlighting and preprocessor skipped regions
- semantic navigation: $ccls/navigate