RFC 2496
Definitions of Managed Object for the DS3/E3 Interface Type. D. Fowler, Ed. January 1999.
http://tools.ietf.org/html/rfc2496

RFC 2798
Definition of the inetOrgPerson LDAP Object Class. M. Smith. April 2000.
http://tools.ietf.org/html/rfc2798

Bill Orcutt's Max/MSP Externals
Includes a shell object, a mySQL client, and other utilities.
http://www.publicbeta.cx/max/

Adaptive Communication Environment
An Object-Oriented Network Programming Toolkit. (C++) [Many platforms]
http://www.cs.wustl.edu/~schmidt/ACE.html

Dome
Distributed Object Migration Environment. Runs on top of PVM. Source code and papers.
http://www.cs.cmu.edu/afs/cs.cmu.edu/project/nectar-adamb/web/Dome.html

Voyager Edge
A object request broker that simultaneously supports CORBA, Web Services and RMI.
http://www.recursionsw.com/Products/voyager.html

Alma
Object-oriented modelling and code migration between languages. [Open Source, GPL]
http://www.desnoix.com/guillaume/alma/

Universe Generator System
Full featured, object oriented and multiplatform 3D engine.
http://ugs3d.sourceforge.net/

Developer Shed - DHTML
Dynamic HTML Developer
http://www.devshed.com/c/b/DHTML/

ZThreads
An advanced object-oriented, cross-platform C++ threading and synchronization library. [GPL]
http://zthread.sourceforge.net/