The 2.0 version of hipSpace for Mac is available as a free download on our website. The program is categorized as Productivity Tools.
From the developer:
hipSpace manages personal information by establishing to them time editable references, namely Objects, and by establishing time editable links between Objects. hipSpace interacts with others applications without impacting their current use. This app records each event (adding, removing, resizing, moving, renaming, linking, unlinking, etc.).
You may want to check out more software for Mac, such as Don't Look Back, Mountee or WeatherScope, which might be related to hipSpace.