Update status: The latest version of Lertap 5 is 22.214.171.124, released 4 December 2019.
The "Useful links" found further down the page do these things:
(1) takes you to the downloads page for all versions, Windows and Mac
(2) links to webpages describing how to upgrade Lertap so that it is not restricted to 100 data records.
(3) links to the "updates summary" for all versions of Lertap.
(4) links out to a website with sample datasets.
(5) leads to a website with some very practical pointers on using Excel and Lertap (includes has examples of Lertap in action).
(6) goes to a website with introduction to practical measurement theory
(7) links to videos demonstrating how to use Lertap
(8) has lecture notes used in the year 2018
(9) links to class references used in 2018
(10) and (11) go to examples of IRT analyses using R packages
(12) a polytomous IRT example for use with RStudio; uses data from the BFI-25 study
(13) links to an R script that will install the packages used by special Lertap macros, such as 'Omega1'
(14) links to a copy of the FIMs original Lertap workbook
(98) takes you out to the Lertap 5 e-store