RB App Quarantine 1.1 (273) is out. It’s the second app in the RB Utilities software suite — RB App Checker Lite was the first one.

As the name implies, it’s a utility that checks or changes the “quarantine” attribute of other applications. This attribute is set whenever an application is directly or indirectly downloaded by the user from anywhere except the Mac App Store. (Applications produced from installer packages, disk images or compressed files inherit the attribute automatically.)

When a quarantined application is first opened or executed, OS X’s Gatekeeper function will check the application’s code signature and several other details and either reject it or throw up the well-known dialog, confirming that you want to execute a downloaded application. If you agree, the quarantine is cleared and Gatekeeper will not check the application again.

Using RB App Quarantine to clear some just-downloaded application’s quarantine attribute is not really recommended: you’ll be bypassing Gatekeeper and — unless you’re a developer yourself and/or have already used RB App Checker Lite to check that application’s bona fides — may be opening your system to a potentially untrusted application.

If you are a developer yourself, using RB App Quarantine to set quarantine on your own application will allow you to check its Gatekeeper status without using Terminal commands or (perish forbid) uploading it to some server and downloading it again.

It took me just 5 days to write this little application since all the UI and other logic common to all RB Utilities is contained in a prepackaged framework and I just had to write the app-specific file/folder handling. Setting up a new project with everything in place and drawing the new icon took a single day. Unfortunately clearing the quarantine attribute takes a special sandbox entitlement which would certainly be frowned upon by the Mac App Store reviewers, so I didn’t even try submitting it.

In other news, I submitted a new version of RB App Checker Lite to the Mac App Store and, if everything goes well, it should be out soon. This new version fixes some bugs and — most requested by users — shows some details pertaining to the latest version of Apple’s Technote 2206, namely showing version 1 and 2 resource rules and showing the Gatekeeper (spctl) assessment results. Stay tuned…