Purpose

• New add-ons, also known as nominations by Firefox, have the potential to harm a user's computer, or to cause instability between the add-on and Firefox itself. By requiring all new potential add-ons to enter into the sandbox, Firefox reviewers can verify that every add-on is safe for use before allowing user's to download and use the add-on. The sandbox also gives the reviewers a chance to look at each add-on and suggest improvements to the developer.
  
  

Process

• Potential add-ons go through a lengthy process before entering the sandbox. A developer uploads the add-on to the Development Hub on Firefox. The add-on is scanned for potential code problems or malware. Once past the validation process, the add-on is nominated by a Firefox reviewer and sent to the sandbox. Add-ons remain in the sandbox until tested and reviewed. Occasionally, Firefox reviewers may work with the developers to improve the add-on before it is released to the public.
  
  

Usage

• General Firefox users cannot access the add-on sandbox. Only Firefox reviewers and testers can view or download add-ons from the sandbox. Developers can also see their pending add-ons in the sandbox. As each add-on is reviewed, the add-ons status will change from either "In Sandbox," for add-ons that still need work, or "Public" for add-ons that are approved for general downloading.
  
  

Other Considerations

• Add-ons in the sandbox are reviewed by both Firefox editors and volunteer reviewers. However, the review time for each add-on varies. Generally, reviewers start with the oldest add-ons for review, but some add-ons require a lengthier testing process, which can delay approval. Firefox posts regular updates regarding the sandbox in the developer forum.