Let's talk about some of the differences between Glitch projects and Thimble projects.
Your Glitch Project Gets Its Own Homepage
Your project on Glitch comes with its own Glitch "homepage" where other community members and the public can view your project. This page shows the project's name and description and an embedded version of your project showing the project's code, the project's own homepage, or both side-by-side. From here you can click one of the available buttons to either remix your project to start editing a new copy or to edit your project directly in the embedded window. You can also open the project's editor window from here.
Changes You Make To Your Glitch Project Go Live Instantly
Probably the biggest change when coming to Glitch from Thimble is the fact that Glitch projects are always live. There's no concept of publishing the project, and any changes you make are also immediately shown in the project's app page. You can use the side-by-side view of the Glitch page as a preview of the app. If you're working in the editor, instead of a preview pane you'll just open the project's web page by clicking on the "Show" button to the right of your project's name, which will open your project's web page in a new tab. For a Thimble preview-like experience you can resize your browser windows to display the two tabs side-by-side.
Glitch Projects Include A README.md
Glitch projects, by default, come with a file called README.md. On your newly-imported Glitch project that file will have some basic tips. But its primary intent is to give people seeing your project for the first time some general information about what your project does and what it's about. It's also a good place to let folks know anything special someone remixing your project might want to know. The file is also shown on your project's Glitch page below the embedded project.
Glitch File Management Doesn't Display A Filetree
Another big difference between Glitch and Thimble is how file management works. At this point Glitch's file manager doesn't show things in a filetree-like display, so "folders" are just a part of the file name. If you want to add a new file to a particular folder just put the folder name in the file name so views/index.html is the index.html file in the views folder. If you want to move a file to a different folder rename it and change the folder name. Folders can also be nested in the same fashion.
File Uploads Work Slightly Different In Glitch
Any files migrated from Thimble will show up in the file list in the same places they were in Thimble. New files can be uploaded either by dragging the file on top of the Glitch window or by using the Upload button in the New File menu in the editor. Glitch will automatically decide where to store a file based on its type: text-based files like HTML, CSS, and JavaScript files will be stored in the regular filesystem and displayed in the file list. Audio and visual files types (images and videos), as well as other things like PDFs will be placed in the assets bucket at the top of the file list. If you want to use one of them in your project you'll need to retrieve it's location by clicking on the file and selecting Copy Url; you can then use the resulting location in your files as you would for any other file.
Click here to see information on migrating from Thimble to Glitch.