WTL

Wtl, or Windows Template Library (WTL), is a C++ library for Windows GUI development that provides a set of template-based classes and utilities to wrap the Win32 API. It is designed to be a lightweight alternative to MFC, offering a smaller footprint and simpler integration with ATL-based code.

Overview

WTL builds on top of the Active Template Library (ATL) and supplies wrappers and helper classes for creating windows, dialogs, and UI controls. It emphasizes performance and compact code, using templates and message maps to route Windows messages to member functions. The library includes wrappers for common controls such as list views, tree views, and combo boxes, as well as utilities for resource handling, graphics (GDI), and basic shell integration.

Architecture and usage

WTL provides classes for window creation and management, including concepts like CWindowImpl, CFrameWindowImpl, and CDialogImpl, which facilitate building standard Windows interfaces. Developers implement message handlers via macros that declare and map messages to member functions. The library is designed to be used in projects that already rely on ATL, and it integrates with the standard Win32 toolchain used by Visual Studio.

Build and ecosystem

WTL is distributed as a set of header files with optional library components. It is typically included in Visual Studio projects by adding its headers to the include path and linking against any necessary libraries. Over the years, it has been maintained through community forks and repositories on platforms such as SourceForge and GitHub, alongside its historical presence in Microsoft’s SDKs.

Overview and status

WTL is regarded as a lightweight, template-based approach to Windows GUI development. While not as widely used as MFC in new projects, it remains in use in some legacy applications and by developers who prefer its lean design and ATL integration.