There was a download of PLA 3.0.0.623 on the developer's website when we last checked. We cannot confirm if there is a free download of this software available. PLA lies within Education Tools, more precisely Science Tools. We recommend checking the downloaded files with any free antivirus. The most popular versions among the program users are 3.0, 2.1 and 2.0. This software is a product of Stegmann Systems. The PLA installer is commonly called PLA 3.0.exe, pla.exe or PlantsVsZombies.exe etc.
From the developer:
PLA is a standard solution for analyzing parallel-line and parallel-logistic (3-, 4- and 5-parameter logistic curve fits) biological assays according to the US Pharmacopoeia bioassay chapters 1032, 1033 and 1034 as well as according to European Pharmacopoeia 6th Edition.
You may want to check out more software, such as StrePla, Kintecus or Drum Machine, which might be related to PLA.