markrae/MudletLessonCalc
This is a package for Mudlet that adds a command for calculating lesson costs for Iron Realms Entertainment games. The basic syntax is LESSONCALC <skillrank> <percentage> TO <skillrank> <percentage>. It also supports using LESSONCALC <skillrank> <percentage> PLUS <number of lessons>. The second usage will calculate how far you'd be in the skill if you added that number of lessons.