CALO Express is part of DARPA's CALO project managed by SRI International. CALO is a learning-based personal assistant that can help organize and prepare information, facilitate communications with others, and automate repetitive tasks. CALO Express is a light-weight, productized subset of CALO that works seamlessly within a Microsoft Windows environment. To learn more about CALO Express,  read the DARPA Brochure (PDF).

CALO and CALO Express in the News
Here's some of our recent press.
Feb 11, 2008:The Last Orion: DARPA funds Artificial Intelligence project
Dec 14, 2007: Semantic Military, Universities Team Up on Big CALO Project
Dec 5, 2007: Tech Daily: SRI's CALO Project Tackles Artificial Intelligence
Nov 20,2007: MIT Tech Review: Software That Learns from Users

Current Release


  • Windows XP
  • MS Office 2003/2007 or Mozilla Thunderbird

  • Minimum hardware requirements:

  • 500 MB RAM
    (1 Gb recommended)
  • 500 MHz
  • 1.5 Gb disk space
  • Our latest release is It is available for download, but you must be part of the CALO project or part of the user's group.  If you're unsure whether you qualify, contact us at
    To download CALO Express you will need a password. 

    CALO Express released – October 30 2009

    Download CALO Express
    CE Users Guide
    View Release Notes

    What CALO Express Can Do
    • Provides Innovative Search
    • CALO Express offers learning-enhanced desktop search across files, contacts, appointments, emails, and news articles. In addition to keyword search, natural language query helps you find exactly what you are looking for (e.g. "Find email from bob about networking"). CALO Express also lets you search meeting transcripts created using CALO Meeting Assistant.

    • Accelerates Presentation Development
    •  CALO Express helps you find the slides you need and assists in discovering other versions of an existing slide.

    • Helps You Prepare for a Meeting
    • CALO Express's PrepPak feature will gather files, emails and other information it thinks might be valuable for you as you prepare for an upcoming meeting, seminar or conference.

    • Keeps You Informed about Relevant News
      After you subscribe to news feeds, CALO will learn your preferences about which articles are most interesting to you and highlight those it believes you will find the most valuable. CALO will also apply this learning to suggest additional news sources you might want to subscribe to.
    Want to Help?
    We are always looking for people to give us their opinions of current and future features and be part of our usability testing. You don't need to be local. Contact and let us know if you're interested.  We also have a user's group you may be eligible to join.