Btrieve

Belov Software
Shareware utilities for Btrieve.
http://bsl.com.ru/

Classic Software, Inc.
Software components and programming tools for Btrieve, including the Classic Data Control for Btrieve and DDF Maker, a utility for editing Btrieve data dictionaries.
http://www.classicsoftware.com/

Nelson Software Solutions - btsearch
Export and import Btrieve data including utilities to edit DDF files or to analyze your existing files or create them.
http://www.nssdd.com/btsearch.htm