Shareware? PDFZilla uses pdftk.exe, pdf2swf.exe, and pdf2htm.exe. I say avoid.
Legal issues ? Ethics ? Please share more.
Let us say an open source project fulfills some function, and a commercial wrapper around the programs is sold. In some cases this could violate a GPL license. Or there could be a simple ethical issue of not acknowledging the source programs. There could be some cases where the value-added, to a commercial product, is sensible. Which level is your concern here.
If it is clear enough then those like Lifehacker should be informed. (They had a page a year ago on an earlier similar giveaway, a number of folks struggled with the registration.)
PDFZilla Batch Converts PDFs to Editable Formats, Is Free Until Februaryhttp://lifehacker.co...-free-until-february
Lifehacker today, on new threads, seems to be making it more difficult to comment, trying to get you to use Facebook or Twitter accounts. That could be another discussions.
The zilla name come s from the excellent FTP Filezilla program.
Use by a totally unrelated company is tacky.