The package provides many (purely expandable) tools for LaTeX: Extensive list management (csv lists, lists of single tokens/characters, etoolbox lists); purely expandable loops (csvloop, forcsvloop, etc.); conversion (csvtolist, etc.)); addition/deletion (csvadd, listdel, etc.); Expansion and group control: \expandnext, \ExpandAfterCmds, \AfterGroup…; Tests on tokens, characters and control sequences (\iffirstchar, \ifiscs, \ifdefcount, \@ifchar…); Tests on strings (\ifstrnum, \ifuppercase, \DeclareStringFilter…); Purely expandable macros with options (\FE@testopt, \FE@ifstar) or modifiers (\FE@modifiers); Some purely expandable numerics (\interval, \locinterplin). The package is dependent on the etex and the etoolbox packages.