Downloading hipSpace 2.0.1 for Mac from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this app available. The actual developer of this free Mac application is Richard Chappuis.
The size of the latest installer available is 23.3 MB. The program lies within Productivity Tools, more precisely Cloud Services. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe.
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 BigCloud Archives, Everport - for moving 37signals' Backpack data to Evernote or MapMan, which might be related to hipSpace.