It's the 3 main ''ores'' of the morestuff mod, Xoron, Zeron and Naqueda. Xoron is used to make the Excalibur sword, Zeron for the Xcalibur, and craft xoron/zeron to make ''Gopper'' which is used to make the very durable Blood sword. The primary use of Naqueda is to make the naqueda reactor, which is used to make mesecon power, but it was removed in this server (naqueda still exists but it can't be made into a reactor)
There are also 4 forms of Magicite, which are used to make 4 different swords that have equal damage/uses but are different ''type'', which the type is useless at this time.
One can also craft a ''steel longsword'' by making a blade (with steel ingots, 3 in a row I think) and crafting a blade on-top of a stick. One can also craft a ''battle axe'' with steel (use SSS SIS XIX where S = steel ingot, I = stick, X = nothing) which is very heavy (long punch interval) and deals a lot of damage. Replace steel ingots with mese to get a more-powerful, lighter battle axe.
Also, if this server uses morestuff v0.2, you can make steel ladders with the same recipe as a normal ladder, but use steel ingots instead of sticks.
In v0.3 I plan to add steel bars that can be used to make ladders and steel-based handles for tools (yesh, steel is heavy so it will decrease swing time some, all other parameters will be the same), and maybe a timer that when a naqueda reactor is placed, it takes X time until it turns into an empty naqueda reactor and you have to craft the reactor with a naqueda lump above it to ''refill'' it. Then maybe a special class of ''mesecons'' that are ''high voltage'' and can power high-voltage mesecon equipment and blow up low-voltage meselamps (yes, I will add a transformer block that will reduce voltage from high-voltage mesecons, so that it is possible to make ''power lines'' throughout a large city)
Resources are abundant; only money is scarce. People should not have to work hard and remain poor just to pay for the needs of survival.
Society can thrive without money - but only if productive members of society are rewarded for being productive.