General

src/warnings.c
Warning and error reporting.

src/longopt.c
Command-line option parsing.

Interpreter

src/embed.c
The Parrot embedding interface.

src/global_setup.c
Global setup.

src/interpreter.c
src/inter_cb.c
src/inter_create.c
src/inter_misc.c
src/inter_run.c
Parrot Interpreter: Callback Function Handling; Creation and Destruction; Misc functions; Run Ops and Methods.

src/exit.c
Exit Handling.

Registers and Stacks

src/gc/register.c
Register handling routines.

src/stacks.c
Stack handling routines for Parrot.

Ops

src/runops_cores.c
Run Loops.

Bytecode

src/packfile/pf_items.c
Parrot Packfile API and utilities.

src/byteorder.c
Byteordering functions.

Data Types

src/datatypes.c
Parrot and native data types functions.

src/hash.c
Hash table.

src/intlist.c
Regex stack handling routines.

src/list.c
List aka array routines.

PMCs

src/pmc.c
The base vtable calling functions.

src/key.c
Base vtable calling functions.

src/sub.c
Subroutines.

src/pmc_freeze.c
Freeze and thaw functionality.

Objects

src/oo.c
Class and object.

Strings

src/string_primitives.c
src/string.c
String Primitives. Parrot Strings.

src/encodings/fixed_8.c
src/encodings/ucs2.c
src/encodings/utf16.c
src/encodings/utf8.c
String encodings

src/charset/ascii.c
src/charset/binary.c
src/charset/iso-8859-1.c
src/charset/unicode.c
String charset

src/misc.c
src/spf_render.c
src/spf_vtable.c
src/utils.c
Miscellaneous, sprintf and utility functions.

Multi-methods

src/multidispatch.c
Multimethod dispatch for binary opcode functions.

Extensions

src/extend.c
Parrot extension interface.

JIT

src/jit.c
src/jit_debug.c
src/jit_debug_xcoff.c
Parrot's JIT subsystem, with support for stabs files.

Exec

src/exec.c
src/exec_save.c
src/exec_start.c
Parrot's native executable subsystem.

IO

src/io/api.c
src/io/buffer.c
src/io/core.c
src/io/filehandle.c
src/io/io_private.h
src/io/io_string.c
src/io/portable.c
src/io/socket_api.c
src/io/socket_unix.c
src/io/socket_win32.c
src/io/unix.c
src/io/utf8.c
src/io/win32.c
Parrot's layer-based I/O subsystem.

Threads

src/thread.c
Thread handling stuff.

src/tsq.c
Thread-safe queues.

Exceptions

src/exceptions.c
Exceptions.

src/events.c
Event handling stuff.

Memory

src/gc/memory.c
Memory allocation.

src/malloc-trace.c

src/gc/resources.c
src/gc/res_lea.c
Allocate and deallocate tracked resources. Resource allocation using malloc.

src/gc/mark_sweep.c
Small Object Pools and general mark/sweep GC behavior.

Garbage Collection

src/gc/api.c
src/gc/gc_malloc.c
src/gc/generational_ms.c
src/gc/incremental_ms.c
src/gc/mark_sweep.c
src/gc/memory.c
src/gc/pools.c
src/gc/register.c
src/gc/res_lea.c
src/gc/resources.c
Parrot's garbage collection subsystem.

Debugging

src/debug.c
src/parrot_debugger.c
Parrot debugging. The Parrot debugger.

src/pbc_disassemble.c
Parrot disassembler.

src/trace.c
Tracing.

examples/c/test_main.c
A sample test program.