Alternatives to Opal for all platforms with any license

Orgzly

Outliner for notes, tasks and to-dos.

Free Open Source Android Android Tablet
Sync with Dropbox To-Do management Add a feature

10 Like
OmniOutliner

OmniOutliner is a start-to-finish writing app. Perfect for collecting information, outlining Big Ideas, adding structure to any sort of writing, and much more. From...

Commercial Mac OS X iPhone iPad
Import feeds from OPML Add a feature

32 Like
OutlineEdit

A beautifully crafted outliner for your Mac: It helps you keep your ideas structured and collected. Use OutlineEdit as an empty canvas to sketch information - for...

Commercial $ $ $ Mac OS X
No features added Add a feature

3 Like
Deep Notes

Deep Notes is a simple hierarchical note pad. You can use it to outline ideas, make to-do lists, or whatever else might need jotting down in a list, hierarchical or not....

Free Mac OS X
No features added Add a feature

1 Like