# MD4C: New implementation in C

**URL:** <https://talk.commonmark.org/t/md4c-new-implementation-in-c/2302>\
**Category:** Implementation\
**Created:** [November 24, 2016, 2:16pm UTC](https://talk.commonmark.org/t/md4c-new-implementation-in-c/2302 "2016-11-24T14:16:19Z")\
**Posts on this page:** 1\
**Showing post:** 13

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**Author:** ![mity](https://cdn.commonmark.org/user_avatar/talk.commonmark.org/mity/32/1040_2.png) [@mity](https://talk.commonmark.org/u/mity)\
**Post date:** [December 4, 2016, 11:27pm UTC](https://talk.commonmark.org/t/md4c-new-implementation-in-c/2302/13 "2016-12-04T23:27:27Z")

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Just a short progress info:

Improved stability a lot. Spent hours with Valgrind and American Fuzzy Lop and fixed all what has been found so far. Afterwards a complete AFL cycle performed without finding any new issues.

CommonMark 0.27 test suite:

- 610 tests pass (~98%)
- 12 tests fail (~2%)

Cmark’s `make bench`:

- CMark: mean = 0.6590, median = 0.6600, stdev = 0.0032
- MD4C: mean = 0.4410, median = 0.4400, stdev = 0.0032 (~ 33.1% faster)

Cmark’s `pathological_tests.py`:

- Cmark: 0m0.803s
- MD4C: 0m0.517s (~ 35.6% faster)

(Tested with current git heads of MD4C and Cmark on a Linux box)

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_[View the full topic](https://talk.commonmark.org/t/md4c-new-implementation-in-c/2302)._