DOS Navigator

DOS Navigator (DN) is an orthodox file manager for DOS, OS/2 and Windows.
Influence of DOS Navigator.
DOS Navigator is an influential early implementation of orthodox file manager (OFM). By implementing three additional types of virtual file systems (VFS): XTree, Briefcase and list-based, DN opened a new generation of OFMs. Also an unlimited number of panels and many new important features make it one of the most powerful (and complex) OFMs.
History.
The initial version of DN I (v 0.90) was released in 1991, and written by Stefan Tanurkov, Andrew Zabolotny and Sergey Melnik (all from Chișinău, Moldova). After that, DN was rewritten using Turbo Vision by Stefan Tanurkov and Dmitry Dotsenko (Dmitry developed DN at Moscow State University). These versions are sometimes referred as DN II.
In 1993, Slava Filimonov invited Stefan to join him to continue producing and publishing DN with joint efforts. Slava also contributed programming new components, design and made countless optimizations and improvements. He wrote a new software key protection system which remained unbreakable for almost four years after its introduction.
DN II was actively developed until the start of 1995, until version 1.35 which should be considered as a milestone in OFM implementations. Several other programmers participated in development after version 1.35. Starting from version 1.37, Slava Filimonov and Ilya Bagdasarov were in charge of bug-fixing. Filimonov and Bagdasarov solely maintained, developed and released versions 1.37 through 1.39. After they left, DN was maintained again by Stefan and newly acquired developer Maxim Masiutin.
In 1998, the development mostly took a bug-fixing direction as Ritlabs' new product The Bat! became a more promising software product with much better commercial potential. The last shareware version was 1.50. In late 1999, Ritlabs decided to make version 1.51 of the DOS Navigator completely free with freely available source code.
Several open source DN branches currently exist including win32/dpmi/os2 version "dn/2" and linux port attempt "dn2l".
Legacy.
Other groups still release software based on the DN open source code, including new features such as support for long filenames, and support for Linux.