Must read threads before doing anything:
http://forum.xda-developers.com/show....php?t=1397120
http://forum.xda-developers.com/show....php?t=1535320 (more info about roms)

Source:
This thread is based on the compilation thread found HERE.


[ROMs]


GINGERBREAD ROMs

- [ROM] XPeria Boss (Continued Xperia Gio) Final

- [ROM] [PORT] SGS2 ICS Clone For Gio!

- [ROM]Crane Rom

- [DEV][ROM][GT-S5660]FingerPrint

- [BACKTOWORK][PORT][ROM][2.3.6 XWKT7] ➣ Adrenaline™ ROM

- [ROM]XperiaTized V10

- [MOD] NostalgiaMod [Beta2.2]

- [ROM][2.3.6]Light Orange

- [ROM] Enhanced236 - stock 2.3.6

- [PORT][ROM]Beats With Smooth Sense V5

- [PORT][ROM]iOS for GIO

- [ROM]SpaceLess V5

- [DEV][PORT][ROM] Dynamite rom

- [ROM] giospeedo

- [ROM][CWM] Stock Gio 2.3.6 ext4 fs

- S5660 - GIOPRO v1.6 (Android 2.3.6)

- [DEV][ROM] GioSII ROM (Android 2.3.6) Galaxy SII Themed! V4[Semi-Final]!

- [ROM & Kernel][2.3.6] ➣ Adrenaline ROM 2nd ™ | Galaxy Gio Edition|

- [DEV][PORT] SGSIIv7

- [DEV] DianXin OS Gio (DX ROM)

- [DEV][ROM & Kernel] BNC-GIO-v1.0-R2 (Android 2.3.6)[update]

- [DEV][ROM & Kernel] Chocobread GIO!!

- [DEV][Rom & Kernel][IMAGINARY ICS GIO][Multi Language]

- [DEV][ROM][GIO] OmegaICS [Stock 2.3.4]

- [DEV][WIP][ROM] giopower V1

- [GT-S5660][ROM] Jonas Hendrickx's ROM v3.1 [2.3.5][XXKS2]

- [ROM][Samsung Galaxy Gio GT-S5660][2.3.5] Particle (beta)

- [dev][port] wp7

- Samsung Galaxy Gio GT-S5660M - ArpegGioMod ROM

- [Rom][DEV] Damn Small Gio



CM9 (ICS) ROMs

- [DEV] CyanogenMod 9.0.0-RC0-GalaxyICS-UNOFFICIAL-nightly

- [ROM][DEV][WIP][ICS] NexusGio Feel the Stock ICS on your Gio [Download ready]

- [DEV][ROM] AOKP Project [4.0.4]

- [ROM][Galaxy SIII] GioSIII V6

- [DEV][PORT][ICS] AOKP Build 34


CM7 ROMs



- [ROM][PORT] Blackberry OS 6.1

- [DEV]CyanogenMod-7.2.0-RC3-gio-KANG

- [DEV]Cyanogenmod 7.2 RC3 by antonio8297

- [PAUSED][ROM][CM7] °•`CleanGinger`•° Pure Google UI

- [PORT][ROM]TouchWiZZed4 U

- [ROM & KERNEL][CM7.2-BASED] CyanMobile eXperience (2.3.8) Release

- [PORT] [ROM] Koogly Mokee FINAL for Gio

- [ROM] CM7.2-DEMOCRACY

- [ROM]CyanogenMOD 7.2 SUPREME

- [ROM]CM7.2 RC3-Apocalypse for GIO FINAL Version-

- [WIP][ROM] DebianDroid - MoltenMotherBoard

- [ROM][PORT][CM7.2] dRoiDGIo

- [PORT] [ROM] CM 7.2-RC3-AA For Gio!

- [Rom][Port] CyanogenMod 7.2.0 RC1 Miracle Edition

- [DEV] CyanogenMod-7.2.0-RC1-gio-UNOFFICIAL

- [ROM][PORT]JoyOS 1.2.1 [UI IMPROVED]

- [ROM][PORT]LewaOS GIO

- [PORT][ROM] SE Live With Walkman UI [CM7.2]

- [No Touchwiz UI][MOD] Mod No touchwiz Ui [Based on CM 7.2]

- [DEV][UNOFFICIAL]CyanogenMod 7.2-GIO

- [ROM + kernel][dev][port] JoyOS 1.1.8

- [MOD][CM7][WIP] LgGio Beta v0.2 Not final yet!

- [ROM][PORT]JOYOS-1.1.0[Feel iOS on Android]

- [PORT][ROM][CM 7.2][HTC Interfeys!]BeautySense[UnrealSmooth]

- [rom]FINAL VERSION PORT BUGS FREE

- [ROM] NightlyFourE 5.1 GIO | Patch #1 | *Stable* *Smooth*

- [DEV][PORT][GIO] MIUI Gingerbread Beta 4b [CM7.2]

- [Kernel & ROM][TeamCooper]RazrUIv4 GIO,The battery Monster

- [GIO] LiGux OS 3.2 RC 2 | *Stable* *Smooth*

- [DEV][PORT] LunaMalaya

- [Mod][CM7.2] HuwaeiGio

- [mod][ICS] ICSGio!

- [DEV][ROM & KERNEL][CM7.2-BASED] CyanMobile initial A (2.3.7) Release

- [MOD][CM7.2] XperiaGio V1.0 Final

- [ROM][2.3.7]CyanogenMod 7.1 KANG

- [mod][CM7][WIP] SenseGio

- [mod][cm7] SlideGioScreen!

- [mod][cm7] WP7Gio

- [mod] [CM7.1] HoneyGio

- [ROM][PORT]Ju AngeeksTM-v1.1[Full Transparant]

- [ROM] Cy4noobsMod-7.1.3.1

- [mod][cm7] Iphone mod cm7

- [MOD][CM7] custom Ice Cream Sandwich Mod CM7.2

- [ROM] TheSeriousMod

- [DEV][2.3.7]CyanogenMod 7.2-GIO-KANG-RC0 build 4

- [DEV] [Samsung Galaxy Gio] [Android 2.3.5][Cyanogenmod 7.1] Cyano Gio project


MIUI ROMs

- [DEV][PORT][GIO] MIUI Gingerbread Beta 4b [CM7.2]

- [DEV][ROM] MIUI4 based on CM9 beta5 from GalaxyICS

- [ROM][MIUI]C-miui-kamyar

- [DEV][ROM] MIUI4 2.2.24-GIO Alpha3-base 4.0.3 (DEVS only)

- [ROM](Teamcooper)MIUI V4 (2.2.17)

- [DEV][ROM] First | MIUI4 2.2.24 | for GIO Beta3 - base 4.0.3 (CM9)


Sense roms

- [DEV][PORT][ROM]HTC Sense 3.5

- [dev][rom[team sense][htc sense 2.1

- [DEV][ROM][WIP]Real HTC Sense 2.1 for GIO


Stock ROMs

- [ROM] S5660XXKTK [21.03.2012][Android 2.3.6] RFS Filesystem!

- [ROM] S5660DXKT8 [08.03.2012][Android 2.3.6] RFS Filesystem!

- [ROM] S5660XXKTI [04.03.2012][Android 2.3.6] RFS Filesystem!

- [ROM] S5660JPKT7 [07.03.2012][Android 2.3.6] RFS Filesystem!

- [ROM] S5660MUGKG3 [25.07.2011][Android 2.3.4] RFS Filesystem!


[RECOVERYs]

- [RECOVERY] GT-S5660M Stock & ClockWorkMod Recovery 5.x

- [RECOVERY]Stock & ClockworkMod 5.0.2.8 Recovery

- [DEV][WIP][Recovery]PX Custom Recovery 0.3.6[BETA][Last Update: Mar 16, 2012]

- [DEV][PORT] RZRecovery 2.1.4 Galaxy GIO GT-S5660

- [AIO][Recovery]All in One Recovery pack[AROMA Installer]



[KERNELs]

- [Kernel]PX-Kernel For Stock & CyanogenMod7 ROM

- [dev][kernel] custom kernel cm7.2

- [Kernel][UPDATE] Delano Custom Kernel of CM or BNC-R2 ROM Samsung Galaxy Gio GT-S5660

- [CF-Root 3.7][Universal] CF-Root Adaptation for Galaxy GIO {Working For GB & CM Roms}

- [Kernel][UPDATE] Delano Custom Kernel Galaxy Gio (not cyanogen) [dell]

- [kernel]Phiexz's custom Kernel, only STOCK ROM


[Bootanimations]

- ICS Boot animation

- [WIP]Bootanimation Pure Android

- Boot animation booting PC

- [Bootanimation] Nexus one

- [Bootanimation] Fake factory reset

- [Bootanimation] LightFlow

- [REQ]Beats Bootanimation (4th post)


[SCRIPTs]

- [CWM][SCRIPTS][TWEAKS] Adrenaline™ Engine | 4.0 | 3/6|

- [SCRIPTS][TWEAKS][CWM]SlaidyBoost-V2.3

- [SCRIPT][Tweaks]LagFreeV1[One Script To Roll Them ALL]

- [MOD][SCRIPTS][Tweaks][Happy new year]SlaidFastMODV2.5


[MODs]

- [MOD] Increase internal memory of your Gio

- [MOD] Improve your battery life tenfold

- Ultimate_Multimedia_Enhacement pack for FIT,MINI,GIO...


[TUTORIALs]

- How to unbrick Samsung Galaxy Gio

- Flash Firmware DXKT4 (2.3.6) Galaxy Gio GT-S5660 with autodeodexing+overclocking

- [Rooting] Galaxy Gio GT-S5660

- Building Android [kernel] from source

- [GUIDE] Unpacking / Packing / Repacking Boot.img's and Recovery.img's

- [Tutorial]Deodexing + Zipaligning Galaxy Gio GT-S5660

- [TUTORIAL] Solution for faster GPS locks

- Universal Gingerbread Root & Unroot 2.3.3 -> 2.3.7+

If something is missing or information is incorrect please pm me.

This thread was made for newcomers and others to find relevant information.
Thread is closed, as there is no need for replies here.
Pm me or OP for suggestions.

YZ.