K-Meleon
K-Meleon's core is a simple shell around a browser engine. K-Meleon implements important features like browsing history, toolbars, and macros with Kplugins. These are dynamically linked library (.dll) files that are loaded when K-Meleon is launched. All Kplugins are stored in the K-Meleon/Kplugins folder. You can turn Kplugins on or off by going to Edit > Configuration (F2) >> K-Meleon Plugins in the browser.
It's possible to download additional Kplugins, but most extensions do not use this API. If you are looking for additional Kplugins, you can visit K-Meleon Extensions Central or search the forums.
For commands to use native Kplugins with your macros, custom menus, or keyboard shortcuts, see the end-user documentation for plugin commands.
If you're interested in developing a Kplugin refer to the links below:
Third-party plugins use the unrelated Netscape Plugin Application Programming Interface (NPAPI) for media plugins. These include things like Flash, Java, Unity, and Silverlight.