Quest Utils is a mod that contains items and blocks that help quest/story based modpacks. It is not a questing system mod but it can be used in combination with one. It is still in early development and currently contains only three blocks:
This mod supports Open Computers and all three blocks can be controlled from a computer program.
All blocks in this mod support the notion of 'saveable state'. That means that you can save and load the contents and current state of these blocks to a json file. This can be done based on the ID's of these blocks (supporting wildcards) so that you can easily make separate json files for various stages in your modpack.
More documentation on this can be found on the Quest Utils wiki.

A mod that helps modpacks based on objectives and/or quests