Penumbra Requiem 1.0 for Mac was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. This Mac application was originally designed by Frictional Games.
The following version: 1.0 is the most frequently downloaded one by the program users. This program is developed for Mac OS X 10.6 or later. The program is included in Games. According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software.
From the developer:
Requiem is a puzzle expansion for Penumbra: Black Plague. The game contains numerous physics based puzzles, spread out over 9 levels with unique settings. The expansion pushes the graphics capabilities of the game as far as it can - while creating the most detailed and dreading environments yet in a Penumbra game.
You may want to check out more Mac applications, such as Penumbra: Necrologue, Penumbra Overture or Shiver: The Lily's Requiem Collector's Edition, which might be related to Penumbra Requiem.