Grim

Grim is the name of the server infrastructure that Polyphony Digital has used for GT5 Prologue throughout GT Sport. It has been superseeded by Vegas in GT7.

Grim1

Grim initially debuted in GT5 Prologue. It is a basic server serving XML content, using SSL for it's traffic encryption.

It also supported libpace aka DLS, Sony's private library/client for P2P connections/torrents, which was used for serving GTTV contents.

Support for PDIPFS Online Patches also came out of the box. It is unknown whether it has been used in GT5 Prologue. It has been used for GT6 hotfixes.

Grim2

The version 2 of grim came with GT5 - not much is known about the changes.

Grim3

GT Sport brought Grim3 which essentially moved away from XML to use a more popular data exchange format, JSON.