Permissions from the mod authors:
IndustrialCraft: IC2 DevTeam http://www.industrial-craft.net/
Applied Energistics: "Yes, I've officially opened up all my restrictions on this." AlgorithmX2 http://ae-mod.info/
Ars Magica: https://dl.dropboxusercontent.com/u/59560916/ars%20perms.PNG
Biomes O Plenty: Q: Can I add this mod to a mod pack? A: Yes, as long as you give proper credit. http://www.minecraftforum.net/topic/1495041-162-forge-biomes-o-plenty-v062-no-more-terrain-stripes/
Borderlands Mod: http://tinyurl.com/lsvgm37 by IrunoHatake. "With proper credit, that should be fine. :)"
Barrels Mod:"This mod is open source and free for anyone to redistribute and modify."
Better Farming:Nothing said. Heres link: http://www.minecraftforum.net/topic/918168-162-smp-forge-better-farming-v340/
Back Tools: Nothing Said. Here: http://www.minecraftforum.net/topic/1508046-152-back-tools-v1-sheathed-weapons-tools/
Carpenter Mod: You're permitted to distribute this mod as part of a mod pack, whether for public or private use. Heres his Link: http://www.minecraftforum.net/topic/1790919-1516forge-carpenters-blocks-v181-slopes-stairs-and-more/
ComputerCraft: I give permission to include ComputerCraft in any and all Minecraft mod packs, provided it is included unmodified. There is no need to ask permission!
Diamond buckets: If you want to put it in a mod pack and release that, go for it, just shoot me a PM to let me know.
Extra Cells: ya use it :D have fun :D
The Camping Mod: Q: Can I use this mod in my modpack? A: Yes, you could also have checked the download page.
Ancient Warfare: Nothing said so here: http://www.minecraftforum.net/topic/1385622-151-ancient-warfare-catapults-and-siege-enginesforgesmpwipdl/
CraftGuide: You may include CraftGuide in mod packs, or distribute it on its own, without any special procedure or permission.
EasyCrafting: This mod is completely open source and anyone can use the code and/or the full mod in their project or modpack if they provide a link back to the mod homepage. http://mods.lepko.net/download
Extra Bees: http://www.minecraftforum.net/topic/1324321-152sspsmpforestry-extra-bees-and-trees-170-revolutionize-your-bee-and-tree-breeding/
Familiars Mod: Nothing I Could find so here! http://www.minecraftforum.net/topic/931546-162sspsmplan-familiars-new-herobrine-notch-chuck-norris/
Forestry: Mod Packs: You are free to add Forestry to your modpack and redistribute it, as long as the modpack is strictly non-profit and none of the other mods are included against their license.
Galacticraft: Can I use this mod in a modpack? Sure, just make sure there's a cearly visible link to my site to the public as they download the mod.
Magic Bees: Modpack Permissions & License Info: You are permitted to redistribute the original Magic Bees mod from the download links in both Public and Private server packs. My implicit permission is granted for all uses.
MiscPeripherals: Modpacks: go ahead and don't ask me
ModularPowersuits: Yes, you may include this mod in your pack.
ModularPowersuits addons: Yes, you can add it to your pack.
OpenBlocks: Yes, you can use these in your mod pack ;-)
OpenPeripherals: Yes, you can use these in your mod pack ;-)
SGCraft: This is free software. You are free to do whatever you want with it.
Thermal Expansion: Great Dev! http://thermalexpansion.wikispaces.com/License
Wholy's Gun Pack: Using Wholy's Gun Pack for GunCus http://www.minecraftforum.net/topic/1808466-162-wholys-weapon-pack-for-guncus-27-jul-2013-weapons-high-definition/