Your first program - Factor Documentation


In this tutorial, we will write a simple Factor program which prompts the user to enter a word, and tests if it is a palindrome (that is, the word is spelled the same backwards and forwards).

In this tutorial, you will learn about basic Factor development tools.

Note: when you come across boxes with Factor code examples, you can click on them to copy and paste the code into your listener, to be run by then hitting ENTER.

Creating a vocabulary for your first program
Writing some logic in your first program
Testing your first program
Extending your first program


This documentation was generated offline from a load-all image. If you want, you can also browse the documentation from within the UI developer tools. See the Factor website for more information.

Factor 0.102 x86.64 (2301, heads/master-7a7f571058, Mar 10 2026 18:04:59)