Redet is a tool for developing and executing regular expressions using any of more than 50 search programs, editors, and programming languages, intended both for developing regular expressions for use elsewhere and as a search tool in its own right. For each program in each locale, a palette showing the available constructs is provided. The properties of each program are determined by runtime tests, which guarantees that they will be correct for the program version and locale. Additional features include persistent history, extensive help, a variety of character entry tools, and the ability to change locale while running. Redet is highly configurable and fully supports Unicode.