I'm was really sorry to see CPN go and now I'm looking for alternatives. The main functionality I'd like to find in a different app are: 1. outliner capacity 2. ability to have multiple outlines in the same file/document 3. ability to link different cells I own omnioutliner but have used it for different purposes than CPN, because it doesn't meet criteria 2. One of the best options I've found so far is NoteTaker, but I've read reports that the app is no longer being developed (http://www.aquaminds.com/). I own and use Devonthink and Evernote and think they are both great, but they don't have a dedicated outlining capacity. Evernote is set up to sync with Outline, but Outline doesn't meat criteria 3. So, at the moment I'm down to: a) Curio. I use and own Curio but the outlining capacity is not as advanced as CPN. b) NeO. This is an unknown entity for me and I haven't found many reviews, but the feature set looks promising (http://d-lit.com/macosx/neo_outliner/index.php) c) Tree. I've used Tree 1 and am considering Tree 2. I don't think it meets criteria 3 but it more or less meets criteria 2 in the form of tabs. Anyone has advice/experiences?