Gemtext is the default markup language of Gemini, but it can be used anywhere. The main design principle of Gemtext is to be easily parsed line-by-line.
All of Gemtext
Headings look like this:
# Level 1
## Level 2
### Level 3
Lists looks like this:
* Item a
* Item b
Quotes look like this:
> First quote
> Second quote
Gemtext introduced rocket links to the markup sphere:
=> target text
Preformatted blocks are toggled with lines beginning with triple backticks
All other lines are simple paragraphs.
You can't nest anything. There is no inline formatting, including inline links. Spaces after the marker are optional.
Gemtext is limited. Expressiveness is really limited. But it is simple!
Relation to other markups
Gemtext is inspired by Markdown. You can feel it in the headings and code blocks for sure. Other elements are taken from there too, but they are present in other places as well.
Only rocket links are invented by Gemtext. It is unclear who started calling such links rocket links. Perhaps, it was me. Probably, it was me.
It is one of the few languages, that are easily parsed both by machines and humans, with the other one being Mycomarkup. Actually, Mycomarkup is a direct descendant of Gemtext. Older versions of Mycorrhiza used Gemtext, but then it was extended to the modern markup.