Your modpack.Alreadytransformed.

Forge 1.7.10 clients rewrite their own code every time they start — transformers, coremods, Mixin — and big packs take minutes to reach the menu. Here that work is done once, at build time, and the result is played by a test client. Download an FTB pack already pre-compiled for Prism Launcher, or pick mods and port your own mix.

Pre-compiled packs →Port your own

Pre-compiled packs

§ 01

Download a pack below (a Prism Launcher instance, a few hundred MB).
In Prism Launcher: Add Instance → Import → choose the zip. Prism downloads Minecraft, Forge and the libraries itself.
It needs Java 21 (a few packs: Java 8, shown on the card). Prism fetches it when Settings → Java → automatically download Java is on; otherwise pick a Java 21 in the instance’s Java settings.
Play. Do not add or remove mods or change the Forge version: the pre-compiled classes are for exactly these mods.

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Each pack is the FTB Team’s original 1.7.10 release, ported here and tested through Prism Launcher’s own launch path on Linux: main menu, a new world, a short walk. Times are from the build machine (software rendering, no GPU). Windows is untested. The packs and their mods belong to their authors — for your own use.

Port your own

§ 02

Your pack

Minecraft 1.7.10 · Forge

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Your client builds

§ 03

Ports you start show up here with live progress, then a download button. Server builds have their own list on the server page.

Measured

§ 04

100→36 sFTB Direwolf20 (109 mods) to the main menu: stock Java 8 → native

100→42 sSame pack, ported for Java 21, launched by Prism Launcher

115→36 sA UniMixins / GTNH-library pack, ported for Java 8

4.4→3.1 GBMemory of the Direwolf20 client, stock vs Java 21 port

Measured on the build machine with software rendering (no GPU): start-up and memory compare well, frame rates do not.

How it works

§ 05

Start-up work, done once.

Stock test

Your pack is first started as it is, on Java 8, by a test player on a virtual screen: main menu, a new single-player world, a short walk, quit. If the pack does not work on its own (two versions of a mod, a missing dependency), you get Forge's own explanation and nothing else is built.

Dump

The client starts again with every coremod and transformer, and at the main menu all of its classes are written out exactly as Forge, the coremods and Mixin left them — including the classes those tools invent while the game runs.

Closed world

The pre-transformed client is started without any transformer, patched where modern Java or a compiled program needs it, and played by the test player again (Java 8, then Java 21). Known problems are fixed automatically and retried.

Your download

A Prism Launcher instance (import the zip; Prism supplies Minecraft, Forge, the libraries and Java 21 and logs you in as usual), and a standalone folder with start scripts (start.sh, start.bat, start-native.sh), Java included if you want. Both are played by the test client once more before you get them — the Prism instance through Prism’s own launch path.

Java 21 or 8

Java 21 is the default. Packs built on Mixin (UniMixins, GTNH libraries, Et Futurum ...) do not fully work on Java 21 yet; choose Java 8 for them — they still start much faster, because the transforming is still done ahead of time.

Limits

Forge 1.7.10 only. The native program is for 64-bit Linux and is not part of the Prism instance. Windows is untested; macOS is not supported. Builds take 10–30 minutes (big packs and native longer) and run one at a time on one machine. Only packs built from this catalog are ported: uploads of existing packs are not taken, because porting runs every mod of the pack on the build machine.

Keep it private

The download contains Minecraft and the pack's mods. It is for your own use; do not redistribute it. Downloads stay available for the last few builds.