IndustrialCraft2 (IC2) is a mod that some users like using alongside Equivalent Exchange. In fact, there are so many players using both together, Equivalent Exchange has created special interactions if it detects that IndustrialCraft is installed along with Equivalent Exchange. Most notably, some of the IC2 items that mod adds to Minecraft are able to be used in the Transmutation Tablet and have an EMC value. Also, all tools added by IC2 (Bronze tools and armor, and Treetaps) can be repaired by Covalence Dust (mid-level for Bronze items, low-level for treetaps) and the Talisman of Repair.

EMC Values

Several "base" materials from IC2 have EMC values. Note that constructed machines, wires, and other items cannot be placed on the transmutation grid, and have no EMC value. Notably, Refined Iron does not have an EMC value, but iron ingots do, Rubber does not, but Sticky Resin, Rubber Wood and Rubber Tree Saplings do. Fuels (Lava Cells and Uranium) cannot be learned initially; they must be processed by another Power Block before they can be learned by the Transmutation Tablet, or master-taught via the Alchemical Tome.
Item

EMC
Sticky Resin

24
Rubber Tree Sapling, Rubber Wood

32
Copper Dust, Copper Ingot

85
Lava Cell

128
Bronze Dust, Bronze Ingot, Tin Dust, Tin Ingot

256
Uranium Ore

4,096

Using EE to aid IC2

As IC2 uses some items slightly differently than vanilla Minecraft, there are some areas where you get a bigger "bang for your EMC" when using EE with IC2:

Rubber/Insulated wires

You cannot directly transmute rubber in EE, so in order to get Rubber (for insulated wires and more), you can transmute some of the things that get converted into rubber. Sticky Resin, Rubber Wood, and Rubber Tree Saplings all can be converted into rubber in an IC2 Extractor. However, Sticky Resin gives 3 Rubber for every Resin, where the others are 1:1. Since Sticky Resin is worth less EMC than Rubber Wood/Sapling, it's highly efficient to build an Extractor and transmute Sticky Resin (8 EMC/Rubber) than Rubber Wood (32 EMC/Rubber).

Bronze

Bronze is a new material in IC2 that can be used to make Tools and Armor. Bronze Tools are more durable than Iron tools ([[#|last longer]]), and can mine the same blocks as Iron, but do so slightly slower. A bronze ingot has the exact same EMC value as an iron ingot, however. Creating your first bronze ingot requires 3/2 copper dust and 1/2 tin dust (255.5 EMC), which is pretty close to the 256 EMC you get out of it, so there's no "bad" or "inefficient" way to create bronze. Once you have a bronze ingot, it can be learned by the Transmutation Tablet, and then any iron or tin ingot or dust can be transmuted into it 1:1.

Generators

Power in IC2 (EC) is generated through Generator machines, some of which run off fuel. The higher-level EE fuels (Mobius Fuel, Aeternalis Fuel, Alchemical Coal, and Blaze Powder) don't work as fuels in IC2 machines. However, EE fuels can be downgraded to "lesser" fuels, for greater quantity. To get the most from your EE fuels, convert them down to Coal (EMC 128), and then again down to Charcoal (32 EMC). EE values Charcoal less than Coal due to Charcoal being a renewable (and therefore infinite) resource, but IC2 makes no distinction. Therefore, every Mobius Fuel (2,048 EMC) can become a full stack (64) of charcoal, to be thrown in a Generator.

Charcoal can also be stepped up to regular Coal to be used in IC2 Coalfuel Cells, which give much more power to Generators, but require a water container (Bucket or Cell), the Macerator, a Compressor, Extractor and Canning Machine (and manual intervention) to generate. Making Biofuel Cells out of Saplings via EE isn't advised, due to using the same amount of EMC for less total energy, despite not needing the water to hydrate the base material or the Macerator to make dust out of it. Make them out of Leaves (8 EMC/plantball) instead for best effect.

IC2's Geothermal Generator runs off of lava buckets or IC2 lava cells to generate EC. Lava source blocks are usually a finite resource in vanilla minecraft, but not with EE! The Volcanite Amulet can create lava buckets using just redstone dust (and an empty bucket to fill), creating an unlimited source of power for a Geothermal Generator, though it's a bit of a tedious, manual process to do, if you don't have another mod like Buildcraft to do it for you. If you don't mind having a ton of buckets in your inventory, you can make Lava Buckets straight from the Transmutation Tablet for the same cost. If you can find a way to process them via EE, Lava Cells can be made right in the Tablet.

UU-Matter

Due to the widely varying values of uu-matter recipes, uu-matter itself has no EMC value, although it can be crafted into things that do. To get the greatest "bang for your buck" in EMC, craft it into Lapis Lazuli for 1944 Matter EMC per uu-matter or Glowstone for 2048 Fuel EMC per uu-matter.

Using IC2 to help EE

Tin

Tin is a fairly common mineral generated in the world by IC2, and it's valued at the same EMC as iron. By default, tin can be used in place of iron to craft buckets, but that's all. Thanks to its identical EMC value, using a Transmutation Tablet, tin can become iron, and craft all the items iron can craft.

Double Ore values

The IC2 Macerator takes one mineral ore and turns it into two mineral dusts, which can then be smelted into two ingots, effectively doubling the output of every ore smelted. This duplicates the effect of the Dark Matter and Red Matter Furnaces, and since the Macerator is much cheaper to create, it's the one to use early in the game. The Dark Matter and Red Matter Furnaces are much faster than the Macerator, so in later game it will probably get replaced, especially because dusts do not produce two ingots per dust in either Furnace. Dusts can also be transmuted directly into the ingot, saving EU/fuel that would have gone to a Furnace. Macerators tend to get extremely heavy use in combination with EE, so it's a good idea to get Overclockers running.

Indestructible Tools

Reaching the Dark Matter Tool tier in EE has the benefit of being indestructible (among other mining modes). IC2 has the Mining Drill (optionally diamond-tipped), Chainsaw, and Mining Laser. While the Mining Laser is more end-game, the Drill and Chainsaw give you indestructible tools a bit earlier than you'd normally obtain Dark Matter Tools.

More: Equivalent exchange also has an addon for Red Power which adds even more opportunities to the game.
Download RedPower here.