Notion
Notion adopts a block-based approach to managing projects, notes, wikis and more. Notion declares itself a bin of building blocks and likens its workflow to combining together LEGO® blocks to create documents, databases, websites, knowledge bases, and more.
Notion allows the creation of hierarchies of pages, which can be filled with blocks. Notion offers a WYSIWYG ("What You See Is What You Get") editor, supporting both Markdown and rich text, to edit these pages and blocks.
Similar to one of the original PKM tools–HyperCard–Notion positions itself as a tool for making tools, striving to offer a toolset to allow users to customize the software to their exact needs. Through the use of templates, users can share these tools within organizations or with the wider public.