He's talking about asheron's call (AC for short)- turbines first mmo and also one of the original 3 pioneering mmos (EQ, UO, AC)
It was a great game and does have many many cool things that could be translated over for DDO.
/fillcomps is one, tho since we usually have no need for more then 1-12 types of components, isn't very important compared to the huge use it had in AC (Asherons call had litterally hundreds of spell components you needed if you were a pure spell caster)
"Peas" were pretty much greenpeas filled with spell components.. Basicly they were added because spell components were rather heavy and caster types could not carry as much as they wanted because of that.. So as an alternative you could take peas, which took up less inventory slots and less weight overall.. But the downside was they werent usable as spell component, but instead had to be splilt first with a Pea-Spliting tool.
I can't see how that would be helpful for DDO since spell components don't weigh much anything.. The closest current idea is spell component bags which the devs are working on.
The name SplitPea was actually a third party program written by fans of AC. It helped you figure out how ot learn spells in asheron's call, as it had a very complex system centered around trial and error and promoted secrecy because the more a spell was cast, the weaker it got.. So high levle wizards would not help other players as it would hinder there own spells, was quite a complex and interesting system, but it was basicly destroyed by this program.. And thus later removed from the game - all spells were converted to scroll form in shops and learned much the same as wizards learn spells in DDO.
I believe the name of the program was used in the game a kudos to the creators. If I remember right, Zyrca developed it something similar ( cant rememver exactly) and was later hired to work on asheron's call, and she is now a dev for DDO too.