Lertap 5 is an Excel application. It requires a copy of Microsoft's Excel program to run in. To date Lertap has been tested with Windows 98, 2000, XP, and NT4. It has also been tested on Macintosh computers, using MacOS 8, 9, and 10.
In all cases, Lertap has been used on computers running English language versions of Excel. Non-English versions of Excel have at times caused problems; for example, the Chinese language version of Excel has posed problems for would-be Lertap users. On the other hand, Thai versions of Excel have been able to run Lertap.
Is it necessary for Lertap users to be expert users of Excel? No. Some knowledge of Excel can be helpful at times, but it's not required.