When comparing Atom vs Ulysses III, the Slant community recommends Ulysses III for most people. In the question“What are the best Markdown editors for OS X?” Ulysses III is ranked 3rd while Atom is ranked 7th. The most important reason people chose Ulysses III is:
A few themes are baked in and a big selection of [user-contributed styles](http://styles.ulyssesapp.com/) to choose from are available on the Ulysses Style Exchange.
Ranked in these QuestionsQuestion Ranking
Pro Extensive list of packages
Atom has a built-in package manager and an extensive list of packages. Packages are written in CoffeeScript.
Pro Built-in package management
Atom was built from the ground up with the community in mind. Package management is therefore a first class feature.
Due to its modular design, almost any aspect of the editor can be changed. Even seemingly core packages, like those taking care of search and replace functionality, can be forked on GitHub, and changed and replaced in the editor.
The documentation for creating new plugins is also great, making it easier for developers to jump in and create plugins for Atom.
Atom can run on Mac, Windows, and Linux.
Pro Free and open source
Atom is free, open source, and written in C++, LESS, and CoffeeScript.
Pro Beginner friendly
One of the goals of Atom is to be a text editor for both experienced and beginner programmers. You can add keyboard shortcuts, change themes, install plugins, and change core settings by clicking through a GUI, or by manually editing config files the old-fashioned way. It has the added advantage of being built using the same engine that powers Google Chrome, so actions like opening and closing tabs feel familiar, even to new or non-programmers.
Pro Multi-line select and edit
Multiple cursors and column selection allow for versatile ways of editing.
ctrl + d will select the current word and each time the command is repeated, it adds the next occurrence of the word to the selection.
ctrl + click or
middle-mouse click will place another cursor in the place that's clicked. Cursors can then be controlled together. This also allows for selecting vertically.
Pro Embedded Git control
Atom will highlight folders, files, and lines that have any uncommitted edits made. It also integrates really well with GitHub.
Pro Command Palette support
The Command Palette permits fuzzy searching all available functions, settings, snippets, etc.
Pro Allows for instant file switching
By pressing Ctrl or Command + T and using fuzzy search, you can look for a file in your project.
Pro Command line integration out of the box
Installing Atom adds two command line commands -
apm. The first one runs the application itself while the second is the Atom Package Manager that's used to add and remove various components from the package listing. While these features can be set up with other editors as well, Atom takes care of them out of the box.
You can theme and customize Atom to your liking.
Pro HiDPI support
Atom has built-in HiDPI support with zero scaling issues.
Pro Modern feel and very customizable and extendable
Pro Vim plugin turns Atom into a modernized vim
Pro Best support for Arduino with Platformio
Arduino is the most important platform for developing embedded systems.
Pro Highly customizable
A few themes are baked in and a big selection of user-contributed styles to choose from are available on the Ulysses Style Exchange.
Pro Does not distract the user
Ulysses has a clean, unobtrusive, easy to overview interface that allows focusing on writing. By default it's split up in 3 panes with sidebar, sheet pane and content pane from left to right. Unnecessary panes can be hidden.
Pro No Markdown syntax knowledge required
Markdown formatting can be applied from the right-click menu, with keyboard shortcuts or from an optional markup bar. Necessary elemants to links, images, and footnotes are added by filling in a popover.
Pro Can paste rich text and import from Word
Pasted rich text and imported Word documents keep their formatting when converted to Markdown.
Pro Attachments can be added
Attachments such as images, text notes, keywords and writing goals can be added to content. And to organize them keywords can be added.
Pro Great tools for organizing and finding files
Ulysses saves everything in the app so there's no file management outside of the editor involved. It organizes content in groups (folders) and sheets (files), has a powerful, easy to use search and allows adding keywords to attachments to help them be organized and found quickly.
Groups can have an unlimited amount of subgroups and the title of subgroup shows up in the pane view. Sheets can be split up, merged, glued together and easily moved around in the sheet pane by dragging and dropping. Great for splitting up larger documents into manageable chunks while still keeping an overview of the whole project and having the ability to move sections around quickly.
Contents of a group can be filtered by text, keywords or change date within headings, code blocks, images or any other marked up text. Filters can contain a combination of conditions and be saved to make a new group. Saved filters can be moved around to different groups and will return filtered results for that group. Selecting multiple groups will show the combined sheets of those groups.
Pro Keyboard navigation
You can operate Ulysses via keyboard only. No need for mouse.
Pro Multiple preview and export options
The editor can export to Plain Text, RTF, Word, HTML, ePub and PDF with customizable styles for each option. It can also preview HTML directly in the browser.
Pro Inline formatting
There's no live-preview pane or an external previewer necessary. Ulysses displays styling inline.
Pro Includes features for not losing place
Ulysses has options for highlighting current line, showing line numbers and enabling typewriter mode. Typewriter mode defines a place on the screen where the cursor should be so eyes are kept focusing in one place on the screen.
Pro Syncs via iCloud
Content can be synchronised across devices via Apple's iCloud.
Pro Comprehensive documentation
Ulysses comes with an excellently written documentation that covers everything there is to know about the software, including an extensive list of keyboard shortcuts as well as short and sweet introduction to Markdown and its benefits.
Pro Allows the user to work anywhere and on any Apple device of their choice
Ulysses is available for both macOS and iOS. This, combined with the cloud syncing allows users to work on their projects using any Apple device they have at the time.
Pro Displays statistics including how long it takes to read the document
The editor tracks statistics that shows how many characters, words, sentences, paragraphs, and pages a document contains and estimated reading time for slow, average, and fast readers. The statistics display in a popover that can be torn-off so it's constantly visible.
Pro Helps get stuff done
Goals such as how many characters, words, sentences, paragraphs, lines or pages should be written can be set to help get motivated.
Pro Powerful organization features
Groups, tagging, and notes for each document.
Pro Helpful support
Staff is helpful in answering questions on how to use the app.
Pro A demo version is available
A time (10hrs) and usage limited demo for Ulysses III is available.
Con Very slow startup time
Atom is very slow to startup, which is a big disadvantage if you are accustomed to using it to make quick changes on your files.
Con High memory usage
Atom has a relatively high memory usage, especially when compared to some other text editors not based on Electron. For those who develop on the go, this also tends to mean shorter battery life.
Con Has difficulty with large text files
Tends to crash or hang with large >(10MB) text files, making it less useful as a general text editor.
Con Slows down exponentially with plugins
Extending it needs sacrificing responsiveness
Con No text UI
Con Doesn't handle RTL (right-to-left text) well
Text can't be highlighted and manipulated properly, cursor isn't displayed visually according to where it is logically (you have to type to find out), and similar issues.
Con Not known when a new window will open
It's not really clear why and when a new window is opened when you open a file out of the tree view.
Atom is not a native application. As such performance is subpar and the lag is especially noticeable on larger projects. It also opens a surprising amount of sub-processes and leaks a considerable amount of memory.
Con Missing additional touches
As Atom is still relatively new, it's missing nice little touches that other text editors have implemented over the years. From simple ease-of-use items like middle-mouse button multi-cursor select, to the ways pasted information from a spreadsheet is interpreted in multi-select situations.
Con Crash and data loss
I lost unsaved changes 2 times when the app crashes.
A bugreport about that was closed automatically after some time, nobody cares.
Con Doesn't recognize some keyboards
Ulysses now operates on a subscription-based model. $4.99/month or $39.99/year. It is not currently possible to pay once and keep it.
Con Overwrites imported markdown files
When previously written markdown files are imported, they're converted to Ulysses' version of Markdown and original files are overwritten.
Con Cannot render code blocks
You can go around this limitation, but it is complex and not so pretty looking as it is in other Markdown Editors.
Con Proprietary file format
Text is saved in a database in proprietary format. Meaning, your notes can't be accessed other than through the app, and cannot be moved other than by exporting them.
Con Automatic switching of sheets can be confusing
Scrolling down when at the bottom of a sheet will switch to next sheet. When unexpected, this behavior can be confusing to some.
Con iOS and Mac versions have to be bought separately
The iOS version costs $24.99 and the macOS version costs $44.99. They have to be bought separately in order to be used on those devices.
Con No proper right-to-left support in PDF
Ulysses lacks right-to-left support that was available in the previous incarnation of this software.