An interchangeable topic or week (day for 2.3.1+) based format that solves the issue of the 'Scroll of Death' when a course has many topics / weeks. All sections except zero have a toggle that displays that section. One or more sections can be displayed at any given time. Toggles are persistent on a per browser session per course basis but can be made to persist longer by a small code change. Full installation instructions, code adaptions and credits are included in the 'Readme.md' file.
If you have a course with more than fifty two sections then currently the toggle persistence will not work for the fifty third section and above. Then you need to upgrade to the Moodle 2.5 version+.
REPORTING ISSUES: When reporting issues you MUST clearly state the full version and release of both Moodle and the Collapsed Topics format as contained within their 'version.php' files - if not it takes me longer to figure out, often resulting in me asking for the details anyway and slowing the process of solving your problem down. It really helps to read the 'Reporting Issues' section in the 'readme' file and upload and describe in detail the issue you are having on the 'Course formats' forum.
NOTE: The latest version incorporates functionality to support new UK / EU Cookie Law which is implemented as a user acceptance in the 1.9 version and no 'cookie' is used at all in 2.x versions.