Chimera/ChimeraX Commercial Licensing

UCSF Chimera and UCSF ChimeraX are each licensed commercially based on a non-exclusive, nontransferable, 3-year license. The two programs are licensed separately. In other words, your company will need to purchase a separate license for each. There are no free evaluation or trial licenses offered for this software. For-profit entities must execute a written License Agreement to gain access.

Chimera vs. ChimeraX:
The capabilities of the two programs overlap significantly but not completely, and where features overlap, they may still differ in detail. Many people currently use both programs. However, if you are trying to choose between the two, here are some considerations. ChimeraX has much better performance with large structures, as well as other major advantages and completely new features. Perhaps most importantly, ChimeraX is under active development and includes a significant subset of Chimera features (with more to come, see the missing features list). Chimera, on the other hand, has effectively reached end-of-life, is no longer being developed, and is only updated for critical maintenance purposes. In addition, a few Chimera tools that rely on web services may stop working in the future because the infrastructure they depend on is obsolete (details...), whereas ChimeraX uses newer software frameworks that extend its life far into the future. For full lists of included tools and commands, see the User Guides: [Chimera] [ChimeraX].

Licensing Costs and License Agreement Forms:
Costs are based on the number of users per Company's Site Location:

These non-refundable fees are assessed per entity and do not include a company's affiliates or subsidiaries. Each affiliate or subsidiary must acquire a separate license from UCSF. For a given user based at a given site, however, there are no restrictions on the number of downloads during the 3-year period of the license; the user could have installations on multiple computers and/or different versions of the program on the same computer (production release, different daily builds, etc..).

License Agreement Process:

  1. If your company is interested in pursuing a License Agreement, please click the applicable link in the Licensing Costs and License Agreement Forms section above to download the form, complete the fillable fields including an authorized signature for the entity, and email this partially executed PDF to UCSF ( To obtain multiple single-user licenses, please fill out a separate copy of the document for each user. **Since the software is provided for a nominal fee compared to similar products on the market, we don’t negotiate changes to the language of the License Agreements.**

  2. UCSF will countersign and return the fully executed version

Payment Process (which can be concurrent with the license agreement process):

  1. For each license, please include the following information in email to UCSF (
    Company Name: 
    Company Site Mailing (Street) Address: 
    Number of Users: 
    Chimera or ChimeraX: 
    Primary User Name: 
    Primary User Email: 
    Accounts Payable Physical Address: 
    Accounts Payable email address: 
  2. UCSF will generate a quote

  3. Client (you or other company representative) should generate and send a Purchase Order to UCSF

  4. UCSF will invoice client under the Purchase Order

  5. Client should send payment via ACH or bank wire transfer (checks are not accepted) and notify UCSF

  6. UCSF will confirm receipt of payment, then issue the software license key along with instructions on how to download the program. The license key will expire no less than 3 years from the date of issuance, even if that is significantly later than the “effective date” in the License Agreement.

System Requirements:
Downloads are available for recent versions of the Windows and macOS operating systems and some Linux distributions; other versions may not be supported. Chimera and ChimeraX are graphics-intensive programs intended for local, interactive use. We do not provide support for using them on compute clusters or virtual machines, or for remote display or remote rendering (details...).

Revised 28-Jul-2022