When comparing Caret vs Boostnote, the Slant community recommends Caret for most people. In the question“What are the best open source Markdown editors for UNIX-like systems?” Caret is ranked 14th while Boostnote is ranked 16th. The most important reason people chose Caret is:
The single pane formats your MD as you write it but retains the markup so you can see what's going on.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Single-pane hybrid interface
The single pane formats your MD as you write it but retains the markup so you can see what's going on.
Pro Has a heading navigator
Hit ⌘ G to see document titles in a hierarchical view, type and use the arrows to navigate.
Pro Has a file manager
Hit ⌘ T to browse current folder, navigate the file system and manage your files and folders, type to search, right click to create / move / rename / delete items.
Pro Supports multiple cursors / selections
Make ten changes at the same time, not one change ten times - lets you edit multiple lines at once, perform quick and selective find and replace, etc.
Pro Supports context commands
Hit "Enter" to fix spelling, convert list to ordered/unordered/task, convert reference link to inline, jump to reference link definition, jump to footnote definition, visit links, etc.
Pro Supports auto-completions
Auto-completion for paths of links and images, keywords in fenced code blocks, emoji, etc.
Pro Offers inline preview for LaTeX math expressions
Renders LaTeX math expressions as soon as you have finished writing them.
Pro Supports "select more" / "select less" commands
Hit ⌥ ↑ to extend the current selection to the next biggest element and ⌥ ↓ to shrink the selection.
Pro Cross platform support
Supports Windows, macOS and Linux.
Pro Markdown support
Pro Free
Pro Open source
See here.
Pro Great for developers
Boostnote is great for developers looking to take programming notes with code snippets and such.
Pro Supports code snippets and syntax highlighting
Boostnote has the ability to store code snippets and comes with syntax highlighting out of the box, supporting many languages.
Pro Works offline
Boostnote doesn't require an internet connection to work. You can write notes offline and sync later.
Pro Global search, tag feature
Pro Comes with many themes
Boostnote comes with many themes out of the box, most of which are popular themes and color schemes for code editors: e.g. 3024, base16, solarized, tomorrow.
Pro vim/emacs key bindings available
Boostnote supports vim/emacs key bindings. If you're a developer familiar with either of them, navigation should be easy to pick up.
Cons
Con Not free
No longer free, try and buy
Con The shortcuts don't toggle formatting
Pressing cmd+B, for example, will begin a bold segment of text, but pressing it again doesn't end that bold segment, it retroactively turns the boldness off. This interrupts writing flow tremendously.
Con Some of the features are not consistent
Con Must use third-party service for sync-ing (Dropbox, etc.)
Boostnote does not have sync-ing capabilities and relies on third-party services to fulfil notes storage. There are additional steps involved to set this up.
Con Can't work in "real" offline mode
Con Very poor syncing
Data loss may occur on syncing.