LAPD stands for Linkage Analysis Using Pedigree Data. This program allows to estimate maximum likelihood allele and two-locus haplotype frequencies, using an Expectation-Maximization algorithm, taking into account family relationships of the individuals. The authors are Laurent Excoffier and Monty Slatkin.
The software can be downloaded directly here.
The sotware can be cited as:
Excoffier, L. and Slatkin, M. (1998) Incorporating genotypes of relatives into a test of linkage disequilibrium, Am. J. Hum. Genet. 162:171-180.