Worklog (WL in short) is an internal tool developed originally by MySQL AB to keep track of tasks and ideas about how to improve the MySQL Server. From the project description: Worklog allows you to track the work you do in various projects and tasks within them. You define projects and tasks, and then file progress reports on tasks as you go along. Monitors time remaining on tasks and projects.
Each new feature and suggestion is entered into this database, including a detailed specification on how to implement it. Each task receives it's own ID, often referred to as WL#nnnn in source code commit messages and bug reports. Worklog is a mixture of a raw TODO-item tracker and a project management tool: tasks can have different priorities and can be assigned to individual developers for implementation, specification or review. Tasks can have interdependencies and time estimates. There is an external view of a subset of the information available currently via the MySQL Forge, you can review and comment on selected tasks there. The source code of WorkLog (Perl) is available from Sourceforge.net as well. However, the version used internally has slightly diverged from the last publicly available release.