This is a preliminary version of the Rust compiler, libraries and tools.

Source layout:

PathDescription
librustc/The self-hosted compiler
liballoc/Rust's core allocation library
libcore/The Rust core library
libdebug/Debugging utilities
libstd/The standard library (imported and linked by default)
libgreen/The M:N runtime library
libnative/The 1:1 runtime library
libsyntax/The Rust parser and pretty-printer
libtest/Rust's test-runner code
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libarena/The arena (a fast but limited) memory allocator
libbacktrace/The libbacktrace library
libcollections/A collection of useful data structures and containers
libflate/Simple compression library
libfmt_macros/Macro support for format strings
libfourcc/Data format identifier library
libgetopts/Get command-line-options library
libglob/Unix glob patterns library
libgraphviz/Generating files for Graphviz
libhexfloat/Hexadecimal floating-point literals
liblibc/Bindings for the C standard library
liblog/Utilities for program-wide and customizable logging
libnum/Extended number support library (complex, rational, etc)
librand/Random numbers and distributions
libregex/Regular expressions
libregex_macros/The regex! syntax extension
libsemver/Rust's semantic versioning library
libserialize/Encode-Decode types library
libsync/Concurrency mechanisms and primitives
libterm/ANSI color library for terminals
libtime/Time operations library
liburl/URL handling lirary
libuuid/UUID's handling code
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rt/The runtime system
rt/rust_*.c- Some of the runtime services
rt/vg- Valgrind headers
rt/msvc- MSVC support
rt/sundown- The Markdown library used by rustdoc
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compiletest/The test runner
test/Testsuite
test/codegen- Tests for the LLVM IR infrastructure
test/compile-fail- Tests that should fail to compile
test/debug-info- Tests for the debuginfo tool
test/run-fail- Tests that should compile, run and fail
test/run-make- Tests that depend on a Makefile infrastructure
test/run-pass- Tests that should compile, run and succeed
test/bench- Benchmarks and miscellaneous
test/pretty- Pretty-printer tests
test/auxiliary- Dependencies of tests
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librustdoc/The Rust API documentation tool
libuv/The libuv submodule
librustuv/Rust libuv support code
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llvm/The LLVM submodule
rustllvm/LLVM support code
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etc/Scripts, editors support, misc

NOTE: This list (especially the second part of the table which contains modules and libraries) is highly volatile and subject to change.