Top all-time · #2489
Jean-Baptiste Kempf
Personal blog · jbkempf.com · on HN as jbkprogrammingsystems
Jean-Baptiste Kempf is a personal blog at jbkempf.com about programming and systems. Since 2011, 33 different Hacker News readers have linked it 55 times, most often “How to properly(?) relicense a large open source project – part 1”. It is still writing: the last post was on 2026-09-25, and you can follow it by feed.
The official website of Jean-Baptiste Kempf, President of VideoLAN, Founder of Kyber, Open Source activist
Most-linked posts?
- How to properly(?) relicense a large open source project – part 15 people · 5 mentions · first linked 2012-11-15
- The answer of VLC about Secunia4 people · 4 mentions · first linked 2013-07-09
- VLC Core is LGPL2 people · 3 mentions · first linked 2012-11-15
- First release of dav1d, the AV1 decoder2 people · 2 mentions · first linked 2018-12-11
- FFmpeg 9.02 people · 2 mentions · first linked 2026-08-04
- /blog/post/2012/How-to-properly-relicense-a-large-open-source-project-part-32 people · 2 mentions · first linked 2015-05-16
- /blog/post/2022/FFmpeg-5.02 people · 2 mentions · first linked 2022-01-17
- dav1d 0.3.0 release: even faster!2 people · 2 mentions · first linked 2019-05-03
- VLC 3.0.7 and security2 people · 2 mentions · first linked 2019-06-10
- VLC 1.2.0 features - Part 1 video output2 people · 2 mentions · first linked 2011-06-05
What Hacker News says?
All major corporate open source projects have a contributor license agreement (CLA) which contributors must sign. Regardless of whether they intend to close the source in the future or not. See the VLC license change fiasco for why CLAs are very good: http://www.jbkempf.com/blog/post/2012/How-to-properly-relice...
Comment linking /blog/post/2012/How-to-properly-relicense-a-large-open-source-project-part-2
on “Microsoft Launches Its .NET Distribution for Linux and Mac”Submitted 15 years of VLC and VideoLAN as a story · 585 points
HN discussion"It turned out the actual player, launched from their compiled app, was a Python wrapper around some VLC libraries" Isn't VLC licensed under the GPL? Or at least was until very recently? http://www.jbkempf.com/blog/post/2012/How-to-properly-relice... Is/was Leaping Brain violating the license? EDIT: the wrapper script is apparently released under the GPL too: http://news.ycombinator.com/item?id=4834834
Comment linking /blog/post/2012/How-to-properly-relicense-a-large-open-source-project
on “Leaping Brain's "Virtually Uncrackable" DRM is just an XOR with "RANDOM_STRING"”Submitted Introducing Dav1d: a new AV1 decoder as a story · 328 points
HN discussion> I'm running 3.0.6 Btw, you should upgrade: http://www.jbkempf.com/blog/post/2019/VLC-3.0.7-and-security
Comment linking /blog/post/2019/VLC-3.0.7-and-security
on “The one who kept VLC free”Submitted VLC Core is LGPL as a story · 251 points
HN discussionThank you for your work. I have a question about copyright assignment. You wrote: >Unlike a lot of large open source projects, authors of VLC keep all their rights on their code, even if the code is minimal. http://www.jbkempf.com/blog/post/2012/How-to-properly-relice... For an entirely new project, would you rather require all contributors to assign copyright to a single entity which then manages licensing or would…
Comment linking /blog/post/2012/How-to-properly-relicense-a-large-open-source-project
on “Why I am pro-GPL”Submitted VLC 3.0.7 and security as a story · 196 points
HN discussionSeriously, most of your facts are wrong. Source: I'm the president of VideoLAN, I did the VLC relicensing[1], and spent a lot of time on GPL/stores compatibility [2]. VLC was GPLv2+ and so was libVLC (the engine library that was spawned from VLC). VLC was put on iOS store as a GPLv2 app, which was not compatible with Apple ToS, and was therefore removed by Apple. At the same time, libVLC was relicensed over 2 years…
Comment linking /blog/post/2012/I-did-it
on “Why I am pro-GPL”Submitted FFmpeg 7.1 release: a tons of codecs as a story · 167 points
HN discussionWell, to be honest, VLC on Mac has this 2 windows paradigm that is very complex to understand those days... I've been working with a designer to try to do this mockup: http://www.jbkempf.com/~jb/VLC_mac.png
Comment linking /~jb/VLC_mac.png
on “Designers, how do we get you guys to contribute to open source projects?”Submitted First release of dav1d, the AV1 decoder as a story · 153 points
HN discussion> because it would be hard (if even possible) to get every ZoL contributor to relicense I think this is the fundamental point that 'ajross disagrees with. First, they could dump the code and rewrite it. That solves the actual problem (getting a ZFS under GPL) without actually relicensing. If the code from non-Oracle owners is small, that's reasonable. Second, they could ignore their copyrights. I believe this is leg…
Comment linking /blog/post/2012/How-to-properly-relicense-a-large-open-source-project-part-3
on “GPL Violations Related to Combining ZFS and Linux”Submitted Dav1d: performance and completion of the first release as a story · 125 points
HN discussionThe really interesting story is the how(linked from main article): Part 2 (probably the more interesting): http://www.jbkempf.com/blog/post/2012/How-to-properly-relice... Part 1: http://www.jbkempf.com/blog/post/2012/How-to-properly-relice...
Comment linking /blog/post/2012/How-to-properly-relicense-a-large-open-source-project
on “VLC Core is LGPL”Submitted Windows Store and the GPL as a story · 53 points
HN discussionI think there are way better resume templates in LaTeX around, like modernCV ( http://www.ctan.org/tex-archive/macros/latex/contrib/modernc... ), example here: http://www.jbkempf.com/documents/JBKempf-resume.pdf ; or CurrVita http://www.ctan.org/tex-archive/macros/latex/contrib/currvit...
Comment linking /documents/JBKempf-resume.pdf
on “A resume template in TeX”Submitted VLC can stream to ChromeCast as a story · 12 points
HN discussionAnswering to "why can they change the license after the fact?" , I think the answer is something close to "Licenses can be changed after the fact, provided the owners/maintainers get permission from each contributor, or rewrite the problematic parts". VLC went through a similar transition (from GPL to LGPL); jbkempf's blogposts about this experience may be of interest to you: - http://www.jbkempf.com/blog/post/2012/…
Comment linking /blog/post/2012/How-to-properly-relicense-a-large-open-source-project-part-3
on “MAME is going completely open-source to be a 'learning tool for developers'”Submitted Announcing VLC for ChromeOS as a story · 8 points
HN discussionSee my blogposts on LGPL relicensing of VLC engine http://www.jbkempf.com/blog/post/2012/I-did-it Note that the relicensing was not done for the iOS port. And the app above the VLC engine is dual licensed GPLv2/MPLv2
Comment linking /blog/post/2012/I-did-it
on “VLC for iOS returns on July 19, rewritten and fully open-sourced”Submitted First release of dav1d, the AV1 decoder as a story · 5 points
HN discussionBlog post about the release: http://www.jbkempf.com/blog/post/2022/FFmpeg-5.0 See "Big API changes and deprecations" to know more about the major version bump.
Comment linking /blog/post/2022/FFmpeg-5.0
on “FFmpeg 5.0”Submitted VLC 3.0.24 Is Out as a story · 4 points
HN discussionSomething like that: http://www.jbkempf.com/blog/post/2022/FFmpeg-5.0
Comment linking /blog/post/2022/FFmpeg-5.0
on “FFmpeg 5.0”Submitted Libdvdread, libdvdnav and libdvdcss releases as a story · 4 points
HN discussionVLC/Jean-Baptiste Kempf rebuttal: http://www.jbkempf.com/blog/post/2013/More-lies-from-Secunia Comments on rebuttal ask "why don't they provide you with working exploit? (in example EIP = 0x41414141)" So someone claims they did attaching an example mkv file? http://seclists.org/fulldisclosure/2013/Jul/71 https://twitter.com/coolkaveh/status/354716804783943680
Comment linking /blog/post/2013/More-lies-from-Secunia
on “VLC threatens to sue Secunia over full disclosure”Submitted 15 years of VLC and VideoLAN (2016) as a story · 3 points
HN discussionDiscussion here: https://news.ycombinator.com/item?id=6015509 Also see the response from VLC: http://www.jbkempf.com/blog/post/2013/More-lies-from-Secunia
Comment linking /blog/post/2013/More-lies-from-Secunia
on “VLC threatens to sue Secunia over full disclosure”Submitted Dav1d 0.9.1: A Ton of Asm as a story · 3 points
HN discussion