||The contents of this article have been cut.
The subject matter of this article contains in-development information that was cut from the final version of an official and/or canonical source and appears in no other canonical source. It may also contain incomplete information since not all cut material is publicly known.
Prospero was one of Valve's first game designs, slated to come out shortly after Half-Life.
The game was to emphasize exploration, an intricate storyline, and combat via "psionic" powers. Influences would have included the video game Myst and the works of Jorge Luis Borges. The protagonist of Prospero (known as "The Librarian" or "Aleph") underwent a series of design changes during the early development of the game. One iteration relied heavily on the use of psionic amplifiers to augment her innate abilities.
As the design of Quiver started to take over some of Prospero initial goals, Prospero evolved into a massively multiplayer game. It was also intended to be distributed with a mix of official and user-created worlds that could be accessed through an in-game library, and each game would be running on its own server. Online distribution, server browser, a friend finder, user-created content and other concepts initially conceived for Prospero would eventually find their way into the Half-Life series, Steam, and Valve's support of fan-made modifications.
In June 2006, Gabe Newell stated that he would like to resume work on Prospero after Team Fortress 2 was completed.
 Behind the scenes
- "Prospero" is the Italian, Portuguese and Spanish version of the first name "Prosper", which comes from the Roman name "Prosperus", which means "prosperous", "fortunate" or "successful" in Latin. The choice of the name may be a nod to the character Prospero, an island-dwelling duke in exile who could perform powerful magic, in Shakespeare's play The Tempest.
- In the Half-Life sound files folder (Steam version), the music files commonly known as "Dimensionless Deepness", "Steam in the Pipes", "Threatening (Short)", "Traveling Through Limbo" and "Vague Voices" are named "prospero01" to "prospero05", which could imply that the tracks were initially made for Prospero.
- In the playable Half-Life 2 leak sound files, Breen can be heard mentioning the "Aleph universe", as a possible early name for the Combine Overworld. This name was probably recycled from Prospero.
- Karl Deckard was involved in every level of the design process for this unreleased game, much of which was later repurposed for the Half-Life series and the Portal series.
Concept art for Miranda by Les Betterly.
Concept art for Aleph/The Librarian.
 External links