Layers of Ulm's Oberon Library:
tasks

Args: general abstraction for arguments
BlockingEvents: blocking distribution of events
BoolArgs: arguments of type BOOLEAN
BoolDisciplines: aliases of TRUE and FALSE
Comments: comment stripping input filter
CrPipes: coroutine pipes
IntArgs: arguments of type INTEGER
Iterators: sequential access of data structures
Jobs: initiation of background tasks
LocalSemaphores: implementation of internal semaphores
NamedObjects: add Names functionality to arbitrary objects
Names: abstraction for name hierarchies
Networks: general abstraction for bidirectional network connections
PathConditions: wait until a path of Names becomes valid
Paths: resolving string constants into name paths
RemoteEvents: support export and import of event types
RemoteIterators: support export and import of iterators
RemoteNames: network interface for Names
RemoteObjects: access of remote objects
RemotePersistentObjects: delegation of PersistentObjects.Write to remote objects
RemoteStreams: support export and import of streams
RobustObjects: proxy objects which survive their original objects
RoundRobin: round robin scheduler
Schedulers: general scheduler interface
Semaphores: general interface for semaphores
Shadows: call-back objects on top of RemoteObjects
StringArgs: string arguments of arbitrary length
Tasks: general task management
UniqueNames: supply unique names