In computer programming, third party software component is a reusable software component developed to be either freely distributed or sold by an entity other than the original vendor of the development platform. The third party software component market thrives because component oriented development improves the efficiency and quality of developing custom applications.

Visual Basic

Microsoft Visual Basic spawned the first commercially viable market for reusable software components. Visual Basic's first extensibility mechanism was the specification for Visual Basic Extensions, commonly known as "custom controls".

In version 4.0 of Visual Basic, the OCX custom control was introduced to replace VBX. OCX was later renamed ActiveX and then COM. In version 7.0 of Visual Basic, also known as VB.NET, Microsoft introduced the .NET Component to replace both VBX and ActiveX. It was still possible to use many ActiveX components in VB.NET by wrapping them in a .NET layer.

See also

• Enterprise Java Beans
• VCL / CLX
• KParts (KDE)