FileMenu Tools
FileMenu Tools lets you customize the context (right-click) menu of Windows Explorer.
RCDefaultApp is a Mac OS X 10.2 or higher preference pane that allows a user to set the default application used for various URL schemes, file extensions, file types...
rcdefaultapp is a mac os x 10.2 or higher preference pane that allows a user to set the default application used for various url schemes, file extensions, file types, mime types, and uniform type identifiers (or utis; macos 10.4 only).
rcdefaultapp also allows setting the application when digital cameras or firewire webcams such as isight are connected to the computer. for completeness sake, there are also settings that mimic the existing "cds and dvds" preference pane, which allows setting the action to take when various types of cds and dvds are inserted into the computer.
mime default-application file-type mime-type file-extension
FileMenu Tools lets you customize the context (right-click) menu of Windows Explorer.
Commercial Windows Windows Explorer
Default Programs Editor is a powerful but simple file association utility for Windows 7, Vista and XP. This free utility has three main functions: context menu editor, auto-play editor, and default programs association editor.
Free Windows
FileTypesMan is an alternative to the File Types tab in the Folder Options of Windows. It displays the list of all file extensions and types registered on your computer.
Free Windows
Context Menu Manager is a collection of utilities bent on providing the necessary means to customize the file association on the system as well as to enrich the context menu for files and folders with new entries.
Commercial Windows
Context Menu Tuner is an application which allows you to customize Explorer's context menu in Windows 10, Windows 7, 8 and 8.1.
Free Windows
Gunners File Type Editor allows you to you to create/modify various properties for file extensions. Each user can have different properties for a file extension. For...
Free Windows
Magic Launch is a preference pane that lets you customize the experience of opening files on your Mac. Open your files using the original application that created them...
Commercial Mac OS X
Replacement for RCDefaultApp, written for macOS Sierra, in Swift 3.
Free Open Source Mac OS X