The theoretical background and technical capabilities of the free liquid surface (nozzle-less) electrospinnig process is described. The process is the basis of both laboratory and industrial production machines known as NanospiderTM and developed by Elmarco s.r.o. Technical capabilities of the machines (productivity, nanofiber layer metrics, and quality) are described in detail. Comparison with competing/complementary technologies is given, e.g. nozzle electrospinning, nano-meltblown, and islets-in-the sea. Application fields for nanofiber materials produced by various methods are discussed. Consistency of the technology performance and production capabilities are demonstrated using an example of polyamide nanofiber air filter media.