| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | Yes |
| Web | — | Yes |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | — |
| Plans published | 1 | 1 |
| Spec score · Personal Knowledge Management Software | 8.7 (#6) | 8.7 (#7) |
| Integrations | Foam documents compatibility with Obsidian vaults and says users can open the same Markdown folder in VS Code with Foam installed. | Notesium provides a Vim/Neovim plugin that uses its CLI for note finding and preview. |
| Platforms | Foam runs as a VS Code extension, and its installation guide says VS Code supports cross-platform use. | The maker says Notesium runs locally on Linux, macOS, and Windows. |
| Purpose | Foam is a personal knowledge management system built on Visual Studio Code and GitHub for organizing research, creating discoverable notes, and publishing knowledge. | Notesium is an indexer for bidirectionally linked notes designed for Zettelkasten and Evergreen note-taking. |