Markdown-Linked Data (MD-LD) — a deterministic, streaming-friendly RDF authoring format that extends Markdown with explicit {...} annotations.

Demo | Repository

MD-LD allows you to author RDF graphs directly in Markdown using explicit {...} annotations:

[my] <tag:alice@example.com,2026:>

# 2024-07-18 {=my:journal-2024-07-18 .my:Event my:date ^^xsd:date}

## A good day {label}

Mood: [Happy] {my:mood}
Energy level: [8] {my:energyLevel ^^xsd:integer}

Met [Sam] {+my:sam .my:Person ?my:attendee} on my regular walk at [Central Park] {+my:central-park ?my:location .my:Place label @en} and talked about [Sunny] {my:weather} weather. 

Activities:

- **Walking** {+#walking ?my:hasActivity .my:Activity label}
- **Reading** {+#reading ?my:hasActivity .my:Activity label}

Generates valid RDF quads - one per each annotation term.

• Prefix folding: Build hierarchical namespaces with lightweight IRI authoring
• Subject declarations: {=IRI} and {=#fragment} for context setting
• Object IRIs: {+IRI} and {+#fragment} for temporary object declarations
• Four predicate forms: p (S→L), ?p (S→O), !p (O→S)
• Type declarations: .Class for rdf:type triples
• Datatypes & language: ^^xsd:date and @en support
• Fragments: Built-in document structuring with {=#fragment}
• Round-trip serialization: Markdown ↔ RDF ↔ Markdown preserves structure