Adds [map] bbcode to a board. Tested with PunBB 1.3, 1.3.4, 1.4.2. To install, just unpack dist/mapbbcode_punbb.zip to %PUNBB%/extensions and install the extension from administrator's menu.
To add proprietary layers (Google, Yandex etc.) you would have to install mapbbcode_proprietary extension. To do that, copy manifest_proprietary.xml to %PUNBB%/extensions/mapbbcode_proprietary/manifest.xml, creating the directory, and install the extension from administrator's panel.
The extension was written by Ilya Zverev and published under WTFPL.