The Journeyman Project: Turbo!

"This game is no longer abandonware" - This is false. The link to GOG goes to the Journeyman Project: Pegasus Prime, which is a remake of the original Journeyman Project: Turbo. It is not identical in any way and is not the same game. The entire look and feel and gameplay of the game is different, it is not a "remaster" but a true "remake". It does contain the same story, however, so if you have not played the series and wish to start there, it is a great place to start. It still would be nice to have the true original preserved in some fashion, however, as the two are not alike at all.

Luckily, there are youtube videos of full playthroughs of the original, but that does lack the joy of playing these games in their original form.

The original game is still excellent and worth experiencing if you are a fan of games such as Myst.