You have access to all of std.range and std.algorithm, most of std.datetime, many functions in std.string and std.digest, and others scattered throughout the std lib. The main thing you'll want to look at is std.experimental.allocator, which has tons of tools for manual memory allocation.

Most of the community packages out there use the GC. Some though are transitioning to a std.experimental.allocator interface, like this containers library https://github.com/economicmodeling/containers

See Sociomantic 's Ocean library. But you don't need to go that far in practice in most uses. If you keep GC heap small, disable the GC in critical code paths, have threads that the GC doesn't get involved in, and use allocators most people will be fine.