GristTorrent is a program Dave installed on his computer using the green and white CD. This program is a plug-in for the Sburb game and displays the amount of grist belonging to each player. Its function seems to allow the players to share Grist with each other. This would allow John to hand out his extra Shale and his other associated grists to the other players for use in their alchemization processes, such as deploying the Punch Designix.
A Grist Gutter is where grist overflow is stored. Each grist has an upper limit on what can be stored. If a grist goes over this limit then it will be sent to the Grist Gutter. The gutter will pass out the grist in the gutter between each user over time.
This is a clear reference to a type of P2P networking known as BitTorrent. BitTorrents allow the user to download bits of data from multiple different versions to create one whole copy of the file. This is somewhat preferred for many power users due to the fact that the seeders (those who have a full version already and are sending out the bits) require little connection to properly seed a torrent and the fact that leechers (those who are retrieving a copy) have multiple sources to choose from. The icons in the lower left hand corner and the green motif of the text suggests that Grist Torrent is based on μTorrent.