diff --git a/packages/cmarkit/cmarkit.0.4.0/opam b/packages/cmarkit/cmarkit.0.4.0/opam
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+++ b/packages/cmarkit/cmarkit.0.4.0/opam
@@ -0,0 +1,69 @@
+opam-version: "2.0"
+synopsis: "CommonMark parser and renderer for OCaml"
+description: """\
+Cmarkit parses the [CommonMark specification]. It provides:
+
+- A CommonMark parser for UTF-8 encoded documents. Link label resolution
+  can be customized and a non-strict parsing mode can be activated to add: 
+  strikethrough, LaTeX math, footnotes, task items and tables.
+  
+- An extensible abstract syntax tree for CommonMark documents with
+  source location tracking and best-effort source layout preservation.
+
+- Abstract syntax tree mapper and folder abstractions for quick and
+  concise tree transformations.
+  
+- Extensible renderers for HTML, LaTeX and CommonMark with source
+  layout preservation.
+
+Cmarkit is distributed under the ISC license. It has no dependencies.
+
+[CommonMark specification]: https://spec.commonmark.org/
+
+Homepage: <https://erratique.ch/software/cmarkit>"""
+maintainer: "Daniel Bünzli <daniel.buenzl i@erratique.ch>"
+authors: "The cmarkit programmers"
+license: "ISC"
+tags: ["codec" "commonmark" "markdown" "org:erratique"]
+homepage: "https://erratique.ch/software/cmarkit"
+doc: "https://erratique.ch/software/cmarkit/doc"
+bug-reports: "https://github.com/dbuenzli/cmarkit/issues"
+depends: [
+  "ocaml" {>= "4.14.0"}
+  "ocamlfind" {build}
+  "ocamlbuild" {build}
+  "topkg" {build & >= "1.1.0"}
+  "uucp" {dev}
+  "b0" {dev & with-test}
+]
+depopts: ["cmdliner"]
+conflicts: [
+  "cmdliner" {< "2.0.0"}
+]
+build: [
+  [
+    "ocaml"
+    "pkg/pkg.ml"
+    "build"
+    "--dev-pkg"
+    "%{dev}%"
+    "--with-cmdliner"
+    "%{cmdliner:installed}%"
+  ]
+  [
+    "cmdliner"
+    "install"
+    "tool-support"
+    "--update-opam-install=%{_:name}%.install"
+    "_build/src/tool/cmarkit_main.native:cmarkit" {ocaml:native}
+    "_build/src/tool/cmarkit_main.byte:cmarkit" {!ocaml:native}
+    "_build/cmdliner-install"
+  ] {cmdliner:installed}
+]
+dev-repo: "git+https://erratique.ch/repos/cmarkit.git"
+url {
+  src: "https://erratique.ch/software/cmarkit/releases/cmarkit-0.4.0.tbz"
+  checksum:
+    "sha512=4f0be18c1a16265710d20b85e48b3f8d8632dd708f413264f2a3b7653a860fd80440b81dc40f5ec63d63411705ae389bb07bdb74365e277bec24895b44ba8a0a"
+}
+x-maintenance-intent: ["(latest)"]
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