Pipmak is an open-source cross-platform game engine and authoring environment. It enables the authoring of point-and-click adventure games, both those in the style of Myst, with slideshow-like images, and those in the style of Myst III: Exile, with 360-degree panoramas. Pipmak effectively "glues" image files together into a game--the images themselves must be created some other way, usually in a 3D rendering program such as POV-Ray or Blender.
The engine is written in C and Lua. Game designers author games for Pipmak by describing nodes (locations in the game) and their corresponding game logic (puzzles, events, interactive object behavior, etc) with Lua scripts. By making the engine use these scripts rather than XML or text files to represent games, the Pipmak developer has given game designers a lot of power and flexibility, though the lack of a GUI for building games might be off-putting to some.
The major technical shortcoming of the engine at the time of this writing is its lack of video file support. The ability to programmatically change a patch's image can simulate a video for a small, short animation, but it's no substitute for actually playing a video, especially in terms of performance. However, since Pipmak is an open source project under some amount of active development, there's hope that such a feature will be added at some point.
If you've been wanting to make a simple, Myst-like game, but have been loath to code the engine yourself, Pipmak will get you most of the way there out of the box. And its small but friendly community is quite accessible, whether you need help getting the application working on your computer or want to add new features to the project.
Pipmak can be downloaded at http://pipmak.sourceforge.net.