Microsoft Office Visio, Xmind, FreeMind, CherryTree, yEd Graph Editor, Notesnook, Mind Mapping 3D, Manuskript, Trilium Notes, LibreOffice - Draw, ProcessMaker, Dendron, Popplet, mindmaps.app, Dynamic Draw, Shosho, Nimbus Note, Cryptee, iMapping, Papier, Flying Logic, mind42, Axon Idea Processor, Aibase, LexiCan, Brainio, Knowte, Thortspace, PMM - Personal Memory Manager, Argumentative, Wisdomap, Xebece, Novamind, Southbeach Modeller, ThinkBook, Versatil Markdown, NodeMind, iBlueSky, Stack for Mac, mySimpleSurface.com, Second Notes, eMindMaps, NoteBox are some alternatives to ThinkComposer.