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+# The API documentation of QMidiPlayer for plugin developers
+
+*This manual is not yet complete. It's only a working draft for the always-changing plugin system in QMP.*
+*Handle with care.*
+
+# 0. Overview
+
+Plugin for QMidiPlayer is a dynamically-loaded library that exports the symbol "qmpPluginGetInterface".
+Before starting developing your own plugin, make sure to have a look at the sample plugin in the "sample-plugin" folder.
+
+# 1. "QMidiPlayer Plugin SDK"
+
+SDK for developing QMidiPlayer plugins is merely the "qmpcorepublic.hpp" header found in the "include" directory in
+the source tree. It includes classes used by QMidiPlayer's internal plugin infrastructure.
+
+# 2. Basics for a working plugin.
+
+First of all, you should make your library distinct from other libraries that are not QMidiPlayer plugins. You can achive
+it by exporting the symbol "qmpPluginGetInterface". Specifically, what you should do is to add the following snipplet to
+somewhere of your code:
+
+> extern "C"{
+>	EXPORTSYM qmpPluginIntf* qmpPluginGetInterface(qmpPluginAPI* api)
+>	//semicolon or implementation here.
+> }
+
+The EXPORTSYM macro tells the compiler to export the following symbol. qmpPluginIntf is the abstract class which every
+plugin class should derive from. The parameter api provides access to QMidiPlayer's plugin API, which should be stored
+for future use.
+
+Next you should create your own plugin class which implements the abstract class "qmpPluginIntf".
+
+# 3. A Peek into the class "qmpPluginIntf"
+
+It has 6 public members: one default constructor, one default destructor and four methods:
+
+- void init()
+  Called on start up if the plugin is loaded successfully and enabled.
+- void deinit()
+  Called on shutdown if the plugin is enabled.
+- const char* pluginGetName()
+  This function should return the display name of the plugin.
+- const char* pluginGetVersion()
+  This function should return the version of the plugin, which will be shown in the plugin manager.
+
+Your plugin is expected to register handlers and functionalities when init() is called by the host,
+and do clean-up jobs when deinit() is caled.