The Visual Component Library (VCL) is a an objected-oriented application framework (software library) developed by Borland International for use with their Delphi compiler to create Microsoft Windows GUI applications. The C++ compiler/IDE that Borland developed - C++ Builder - can also use VCL to develop Windows GUI applications. A cross-platform equivalent to the VCL library was also created and called CLX. It was available for Delphi 7 and Kylix (a Linux version of Delphi).
The Free Pascal equivalent to VCL is the Lazarus Component Library (LCL).
In 2011 Embarcadero Technologies (who purchased Borland's software development products) began offering Delphi and C++ Builder developers an alternative GUI framework called FireMonkey. In addition to Microsoft Windows, FireMonkey can be used on Android, iOS, and OS X.