What Is ATL?
ATL stands for Active Template Library. However, this expansion doesnt fully convey what ATL contains. The word Active in ATL is really a remnant of Microsoft’s old marketing strategy when everything related with COM was ActiveX. Today, the meaning of ActiveX is limited to controls. These controls can be developed, using ATL. But ATL can do much more than merely building ActiveX controls. COM components can be developed using MFC. However, such components suffer from two limitations: • Size of the COM component often becomes unduly large. This is because most COM components developed using MFC, require run-time libraries like mfc42.dll to execute. Bundling this library along with the COM object results in a very large file size. When such components are used over networks, the performance suffers. • It becomes very difficult to change the default functionality of the component. Instead of using MFC, if we use Active Template Library (ATL), we can easily build small, self-contained, and
