A world editor for Terra - A Terraria Demake.
This is an early version, there are a few bugs here and there, but I'm uploading it now so people have access to it. Post your creations!
Controls
You need a keyboard and mouse to use Terra-Edit.
Move view - Arrow Keys or ESDF
Tile palette - Tab
Tool action - Left click
Tool alt action - Right click
System menu - Enter
Editing
Terra-Edit starts with a world selection screen. Navigate this with the arrow keys and ZX.
You can drop an existing world file to edit, or generate a new world using one of the other options. Once you have a world open, you can move the camera around with the arrow keys.
Select tools by clicking them along the top bar. Most tools have a tooltip at the bottom of the screen saying what the tool can do.
Once you're done editing, press Enter or click the wrench icon to open the system menu, where you can find the option to save your world. From this point, saving works exactly the same as Terra, so refer to that if needed.
Also in the system menu, you can find a few options to toggle certain rendering features like lighting and treetops.
Known Issues

When lighting is enabled, the UI darkens as well, in much the same way as Terra. Unlike Terra, this can be resolved easily as Terra-Edit's UI covers entire scanlines instead of arbitrary shapes.
Tiles selected by the copy tool follow the cursor when it's over the toolbar.
Tile selections may behave oddly when changing tools with a selection active.
The code is kind of bad. Like code-spaghetti bad. I need a bit more experience making editors.