wxWidgets provides a set of classes that implement an extensible virtual file system, used internally by the HTML classes. \overview{Drag and drop and clipboard overview}{wxdndoverview} wxWidgets has several small classes to work with disk files, see \helpref{file classes overview}{wxfileoverview} for more details. wxWidgets has its own set of stream classes, as an alternative to often buggy standard stream libraries, and to provide enhanced functionality. \overview{XML-based resource system (XRC) overview}{xrcoverview} Resources allow your application to create controls and other user interface elements from specifications stored in an XML format. There are several types of window that are directly controlled by the window manager (such as MS Windows, or the Motif Window Manager). Frames and dialogs are similar in wxWidgets, but only dialogs may be modal. \overview{Overview}{wxlogoverview} wxWidgets provides several classes and functions for message logging. Please see the \helpref{wxLog overview}{wxlogoverview} for more details. \overview{Overview}{printingoverview} A printing and previewing framework is implemented to make it relatively straightforward to provide document printing facilities. The following are a variety of classes that are derived from wxWindow. \overview{Overview}{validatoroverview} These are the window validators, used for filtering and validating user input. \overview{Overview}{commondialogsoverview} Common dialogs are ready-made dialog classes which are frequently used in an application. \overview{Overview}{ipcoverview} wxWidgets provides simple interprocess communications facilities based on Windows DDE, but available on most platforms using TCP. \overview{Overview}{runtimeclassoverview} wxWidgets supports run-time manipulation of class information, and dynamic creation of objects given class names. wxWidgets provides its own classes for socket based networking. \overview{Bitmaps overview}{wxbitmapoverview} These classes are related to drawing on device contexts and windows. There are two different systems for laying out windows (and dialogs in particular). One is based upon so-called sizers and it requires less typing, thinking and calculating and will in almost all cases produce dialogs looking equally well on all platforms, the other is based on so-called constraints and is deprecated, though still available. \overview{Sizer overview}{sizeroverview} describes sizer-based layout. These are the classes relevant to sizer-based layout. These are the data structure classes supported by wxWidgets. \overview{Multithreading overview}{wxthreadoverview} wxWidgets provides a set of classes to make use of the native thread capabilities of the various platforms. \overview{Overview}{docviewoverview} wxWidgets supports a document/view framework which provides housekeeping for a document-centric application. \overview{Database classes overview}{odbcoverview} wxWidgets provides a set of classes for accessing Microsoft's ODBC (Open Database Connectivity) product, donated by Remstar. This is known as wxODBC. \overview{Overview}{eventhandlingoverview} An event object contains information about a specific event. Event handlers (usually member functions) have a single, event argument. \overview{Overview}{dcoverview} Device contexts are surfaces that may be drawn on, and provide an abstraction that allows parameterisation of your drawing code by passing different device contexts. wxWidgets provides a set of classes to display text in HTML format. These class include a help system based on the HTML widget. \overview{Overview}{debuggingoverview} wxWidgets supports some aspects of debugging an application through classes, functions and macros. Typically, these are small windows which provide interaction with the user. Controls that are not static can have \helpref{validators}{wxvalidator} associated with them.