Arg	Parsing of command line arguments.
Array	Array operations.
ArrayLabels	Array operations.
Buffer	Extensible buffers.
Bytes	Byte sequence operations.
BytesLabels	Byte sequence operations.
Callback	Registering OCaml values with the C runtime.
Char	Character operations.
Complex	Complex numbers.
Digest	MD5 message digest.
Dynlink	Dynamic loading of object files.
Ephemeron	Ephemerons and weak hash table
Event	First-class synchronous communication.
Filename	Operations on file names.
Format	Pretty-printing.
Gc	Memory management control and statistics; finalised values.
Genlex	A generic lexical analyzer.
Graphics	Machine-independent graphics primitives.
GraphicsX11	Additional graphics primitives for the X Windows system.
Hashtbl	Hash tables and hash functions.
Int32	32-bit integers.
Int64	64-bit integers.
Lazy	Deferred computations.
Lexing	The run-time library for lexers generated by `ocamllex`.
List	List operations.
ListLabels	List operations.
Map	Association tables over ordered types.
Marshal	Marshaling of data structures.
MoreLabels	Extra labeled libraries.
Mutex	Locks for mutual exclusion.
Nativeint	Processor-native integers.
Obj	Operations on internal representations of values.
Oo	Operations on objects
Parsing	The run-time library for parsers generated by `ocamlyacc`.
Pervasives	The initially opened module.
Printexc	Facilities for printing exceptions and inspecting current call stack.
Printf	Formatted output functions.
Queue	First-in first-out queues.
Random	Pseudo-random number generators (PRNG).
Scanf	Formatted input functions.
Set	Sets over ordered types.
Sort	Sorting and merging lists.
Spacetime	Profiling of a program's space behaviour over time.
Stack	Last-in first-out stacks.
StdLabels	Standard labeled libraries.
Str	Regular expressions and high-level string processing
Stream	Streams and parsers.
String	String operations.
StringLabels	String operations.
Sys	System interface.
Uchar	Unicode characters.
Weak	Arrays of weak pointers and hash sets of weak pointers.