OLE type library files (Microsoft)
TLB is a file extension for Object Linking and Embedding (OLE) type library file format used by Microsoft Visual C++ software development program, part of Microsoft's ActiveX technologies. OLE is Microsoft's framework for a compound document technology.
Briefly, a compound document is something like a display desktop that can contain visual and information objects of all kinds: text, calendars, animations, sound, motion video, 3-D, continually updated news, controls, and so forth.
TLB files are created in Visual Basic when an OLE or ActiveX server is created.
Learn more about TLB files:
Development expert Matt Billingham sheds light on OLE functionality for populating Excel files.
Search for answers to OLE-related questions at IT Knowledge Exchange.
Visit the Microsoft Visual C++ web page.