Yasminuroban is an open source "Sokoban" alike game totally written in DHTML (JavaScript, CSS and HTML) that uses keyboard. Includes level editor.
This cross-platform and cross-browser game was tested under BeOS, Linux, NetBSD, OpenBSD, FreeBSD, MacOS, Windows and others.
Only you need a DHTML compatible web browser with JavaScript enabled to play it.
You can edit your own levels with the level editor and play with it.
Also, you can edit source code of the game and include more levels, change graphics, include improves, etc... You only need to maintain author name and don't change it.
JavaScript is a interpreted language, like Java, Flash, Python, etc. But JavaScript doesn't need any plugin to install!