Markdig

Markdig is a fast, powerful, CommonMark compliant, extensible Markdown processor for .NET.

NOTE: The repository is under construction. There will be a dedicated website and proper documentation at some point!

You can try Markdig online and compare it to other implementations on babelmark3

Features

• Very fast parser and html renderer (no-regexp), very lightweight in terms of GC pressure. See benchmarks
• Abstract Syntax Tree with precise source code location for syntax tree, useful when building a Markdown editor.
  • Checkout MarkdownEditor for Visual Studio powered by Markdig!
• Converter to HTML
• Passing more than 600+ tests from the latest CommonMark specs (0.28)
• Includes all the core elements of CommonMark:
  • including GFM fenced code blocks.
• Extensible architecture
  • Even the core Markdown/CommonMark parsing is pluggable, so it allows to disable builtin Markdown/Commonmark parsing (e.g Disable HTML parsing) or change behaviour (e.g change matching # of a headers with @)
• Built-in with 20+ extensions, including:
  • 2 kind of tables:
    • Pipe tables (inspired from Github tables and PanDoc - Pipe Tables)
    • Grid tables (inspired from Pandoc - Grid Tables)
  • Extra emphasis (inspired from Pandoc - Emphasis and Markdown-it)
    • strike through ~~,
    • Subscript ~
    • Superscript ^
    • Inserted ++
    • Marked ==
  • Special attributes or attached HTML attributes (inspired from PHP Markdown Extra - Special Attributes)
  • Definition lists (inspired from PHP Markdown Extra - Definitions Lists)
  • Footnotes (inspired from PHP Markdown Extra - Footnotes)
  • Auto-identifiers for headings (similar to Pandoc - Auto Identifiers)
  • Auto-links generates links if a text starts with http:// or https:// or ftp:// or mailto: or www.xxx.yyy
  • Task Lists inspired from Github Task lists.
  • Extra bullet lists, supporting alpha bullet a. b. and roman bullet (i, ii...etc.)
  • Media support for media url (youtube, vimeo, mp4...etc.) (inspired from this CommonMark discussion)
  • Abbreviations (inspired from PHP Markdown Extra - Abbreviations)
  • Citation text by enclosing ""..."" (inspired by this CommonMark discussion )
  • Custom containers similar to fenced code block ::: for generating a proper <div>...</div> instead (inspired by this CommonMark discussion )
  • Figures (inspired from this CommonMark discussion)
  • Footers (inspired from this CommonMark discussion)
  • Mathematics/Latex extension by enclosing $$ for block and $ for inline math (inspired from this CommonMark discussion)
  • Soft lines as hard lines
  • Emoji support (inspired from Markdown-it)
  • SmartyPants (inspired from Daring Fireball - SmartyPants)
  • Bootstrap class (to output bootstrap class)
  • Diagrams extension whenever a fenced code block contains a special keyword, it will be converted to a div block with the content as-is (currently, supports only for mermaid diagrams)
  • YAML frontmatter to parse without evaluating the frontmatter and to discard it from the HTML output (typically used for previewing without the frontmatter in MarkdownEditor)
  • JIRA links to automatically generate links for JIRA project references (Thanks to @clarkd: https://github.com/clarkd/MarkdigJiraLinker)
• Compatible with .NET 3.5, 4.0+ and .NET Core (netstandard1.1+)

Documentation

The repository is under construction. There will be a dedicated website and proper documentation at some point!

While there is not yet a dedicated documentation, you can find from the specs documentation how to use these extensions.

In the meantime, you can have a "behind the scene" article about Markdig in my blog post "Implementing a Markdown Engine for .NET"

Download

Markdig is available as a NuGet package:

Also Markdig.Signed NuGet package provides signed assemblies.

Usage

The main entry point for the API is the Markdig.Markdown class:

By default, without any options, Markdig is using the plain CommonMark parser:

var result = Markdown.ToHtml("This is a text with some *emphasis*");
Console.WriteLine(result);   // prints: <p>This is a text with some <em>emphasis</em></p>

In order to activate most of all advanced extensions (except Emoji, SoftLine as HardLine, JiraLinks and SmartyPants)

// Configure the pipeline with all advanced extensions active
var pipeline = new MarkdownPipelineBuilder().UseAdvancedExtensions().Build();
var result = Markdown.ToHtml("This is a text with some *emphasis*", pipeline);

You can have a look at the MarkdownExtensions that describes all actionable extensions (by modifying the MarkdownPipeline)

Build

In order to build Markdig, you need to install .NET Core RTM

License

This software is released under the BSD-Clause 2 license.

Benchmarking

This is an early preview of the benchmarking against various implementations:

C implementations:

• cmark (version: 0.25.0): Reference C implementation of CommonMark, no support for extensions
• Moonshine (version: : popular C Markdown processor

.NET implementations:

• Markdig (version: 0.5.x): itself
• CommonMark.NET(master) (version: 0.11.0): CommonMark implementation for .NET, no support for extensions, port of cmark
  • CommonMark.NET(pipe_tables): An evolution of CommonMark.NET, supports extensions, not released yet
• MarkdownDeep (version: 1.5.0): another .NET implementation
• MarkdownSharp (version: 1.13.0): Open source C# implementation of Markdown processor, as featured on Stack Overflow, regexp based.
• Marked.NET (version: 1.0.5) port of original marked.js project
• Microsoft.DocAsCode.MarkdownLite (version: 2.0.1) used by the docfx project

JavaScript/V8 implementations:

• Strike.V8 (version: 1.5.0) marked.js running in Google V8 (not .NET based)

Analysis of the results:

• Markdig is roughly x100 times faster than MarkdownSharp, 30x times faster than docfx
• Among the best in CPU, Extremely competitive and often faster than other implementations (not feature wise equivalent)
• 15% to 30% less allocations and GC pressure

Because Marked.NET, MarkdownSharp and DocAsCode.MarkdownLite are way too slow, they are not included in the following charts:

Performance for x86:

BenchmarkDotNet-Dev=v0.9.7.0+
OS=Microsoft Windows NT 6.2.9200.0
Processor=Intel(R) Core(TM) i7-4770 CPU 3.40GHz, ProcessorCount=8
Frequency=3319351 ticks, Resolution=301.2637 ns, Timer=TSC
HostCLR=MS.NET 4.0.30319.42000, Arch=32-bit RELEASE
JitModules=clrjit-v4.6.1080.0

Type=Program  Mode=SingleRun  LaunchCount=2
WarmupCount=2  TargetCount=10

                     Method |      Median |    StdDev |Scaled |  Gen 0 | Gen 1|    Gen 2|Bytes Allocated/Op |
--------------------------- |------------ |---------- |------ | ------ |------|---------|------------------ |
                    Markdig |   5.5316 ms | 0.0372 ms |  0.71 |   56.00| 21.00|    49.00|      1,285,917.31 |
     CommonMark.NET(master) |   4.7035 ms | 0.0422 ms |  0.60 |  113.00|  7.00|    49.00|      1,502,404.60 |
CommonMark.NET(pipe_tables) |   5.6164 ms | 0.0298 ms |  0.72 |  111.00| 56.00|    49.00|      1,863,128.13 |
               MarkdownDeep |   7.8193 ms | 0.0334 ms |  1.00 |  120.00| 56.00|    49.00|      1,884,854.85 |
                      cmark |   4.2698 ms | 0.1526 ms |  0.55 |       -|     -|        -|                NA |
                  Moonshine |   6.0929 ms | 0.1053 ms |  1.28 |       -|     -|        -|                NA |
                  Strike.V8 |  10.5895 ms | 0.0492 ms |  1.35 |       -|     -|        -|                NA |
                 Marked.NET | 207.3169 ms | 5.2628 ms | 26.51 |    0.00|  0.00|     0.00|    303,125,228.65 |
              MarkdownSharp | 675.0185 ms | 2.8447 ms | 86.32 |   40.00| 27.00|    41.00|      2,413,394.17 |
Microsoft DocfxMarkdownLite | 166.3357 ms | 0.4529 ms | 21.27 |4,452.00|948.00|11,167.00|    180,218,359.60 |

Performance for x64:

BenchmarkDotNet-Dev=v0.9.6.0+
OS=Microsoft Windows NT 6.2.9200.0
Processor=Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz, ProcessorCount=8
Frequency=3319351 ticks, Resolution=301.2637 ns, Timer=TSC
HostCLR=MS.NET 4.0.30319.42000, Arch=64-bit RELEASE [RyuJIT]
JitModules=clrjit-v4.6.1080.0

Type=Program  Mode=SingleRun  LaunchCount=2
WarmupCount=2  TargetCount=10

               Method |    Median |    StdDev |  Gen 0 |  Gen 1 | Gen 2 | Bytes Allocated/Op |
--------------------- |---------- |---------- |------- |------- |------ |------------------- |
          TestMarkdig | 5.5276 ms | 0.0402 ms | 109.00 |  96.00 | 84.00 |       1,537,027.66 |
    TestCommonMarkNet | 4.4661 ms | 0.1190 ms | 157.00 |  96.00 | 84.00 |       1,747,432.06 |
 TestCommonMarkNetNew | 5.3151 ms | 0.0815 ms | 229.00 | 168.00 | 84.00 |       2,323,922.97 |
     TestMarkdownDeep | 7.4076 ms | 0.0617 ms | 318.00 | 186.00 | 84.00 |       2,576,728.69 |

Donate

If you are using this library and find it useful for your project, please consider a donation for it!

Credits

Thanks to the fantastic work done by John Mac Farlane for the CommonMark specs and all the people involved in making Markdown a better standard!

This project would not have been possible without this huge foundation.

Thanks also to the project BenchmarkDotNet that makes benchmarking so easy to setup!

Some decoding part (e.g HTML EntityHelper.cs) have been re-used from CommonMark.NET

Thanks to the work done by @clarkd on the JIRA Link extension (https://github.com/clarkd/MarkdigJiraLinker), now included with this project!

Author

Alexandre MUTEL aka xoofx