Opal is described as 'lets you organize just about anything — ideas, reports, lists, notes, projects, graphics — in the form of an outline. If you used Acta, you’ll love Opal'. There are five alternatives to Opal for a variety of platforms, including Mac, Windows, Android, iPhone and Android Tablet. The best alternative is Orgzly, which is both free and Open Source. Other great apps like Opal are OmniOutliner (Paid), Visual Outliner (Freemium), OutlineEdit (Free) and Deep Notes (Free).
- 5 alternatives
- Visual Outliner is an outliner software for Windows, and it uses OPML as native file format. It's not just another tasklist application, but a real outliner editor that can be used to write, view, modify, and maintain hierarchically arranged text. View 78 alternatives to Visual Outliner
- Freemium • Proprietary