Periodic Table is an Ace alternative to ReagentData (with some added extras). Like most Ace addons it's focus is low resource usage.
Please note this is NOT an Ace'd version of ReagentData, I used RD's base data as a good portion of the set info, but this mod is not designed to be a drop-in replacement. One of the major points of this mod is an attempt to push more people into using ItemID's in their mods, not item-name strings. Another big point is that not all the data in RD was used, and data from a number of other sources was included. Check the lua files for more details on where data was pulled from.
All of the set info from RD has been converted over. Items are no longer referenced by name strings, but rather by ItemID. This gives two advantages: lowor memory requirements and automatic localization (ItemIDs are locale-independant). Tradeskill recepies were not converted as I didn't see much neede for them and they were not the functionality this mod was aiming to provide. Item sets are stored as a space-delimited string and parsed out into a table only if requested. This speeds up load time and ensures that memory is only used for sets that are activly used. As a comparison with Warmup, RD pulls 1202 KiB and takes 0.362 sec to load, where PT takes 66 KiB and 0.007 seconds (on my crappy slow system).
If you are interested in using PT with your mod feel free to read the source code (there's not a lot). The comments will tell you everything you need to know.
For more info and the latest build please visit AceWiki
Please direct all feedback to my portal (the links under the download button)