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SIO2 No Longer Open Source


Tony Mullen, author of '3D for iPhone Apps with Blender and SIO2' reports that SIO2 has abandoned its open source license.

Tony writes:

Hi Everybody,

I'd like to let people know about an update regarding my book "3D for iPhone Apps with Blender and SIO2: Your Guide to Creating 3D Games and More with Open-Source Software."

Unfortunately, the title is no longer accurate. The book and cover copy were written based on SIO2's license at the time. At that time SIO2 billed itself as "open source" throughout its web page.

Since then, SIO2 has upgraded, and with the new version it has changed its licensing and discontinued availability of the free-of-charge version of the software.

I asked Romain Marucchi-Foino, head of SIO2, if it would be possible for Sybex to make the "open source" version (version 1.4) available from the book's website, but he declined to give me permission to do this.

For people interested in a truly open source solution for iPhone game development I would like to recommend the GameKit project.

Best regards,


About the Author

Bart Veldhuizen

I have a LONG history with Blender - I wrote some of the earliest Blender tutorials, worked for Not a Number and helped run the crowdfunding campaign that open sourced Blender (the first one on the internet!). I founded BlenderNation in 2006 and have been editing it every single day since then ;-) I also run the Blender Artists forum and I'm Head of Community at Sketchfab.


  1. MonkeyOnMyShoulder on

    Sounds like a drug dealer method to me... your first take is totally free !
    But then, when you'll get accustomed to the point you can't live without it, you'll have to pay the hard price.

    That's quite an "unpleasant method" (the words in my head are quite more radical, but let stay polite)...

    Anyway, how can this be even possible to call something "open source" when it can any time get closed-source and commercial ? Shouldn't the naming "open source" be only authorized when it really be intended to be free, not a commercial act in disguise ? Shouldn't there be more legal constraints over the naming ?

    I didn't use it, but I'm sorry for those who were.
    I hope there won't be some cool projects collapsing because of that sneaky move...

  2. MonkeyOnMyShoulder on

    After going to their website, it seems a bit less bad than what I understood in the first place : there is still the 1.4 "free edition".
    They made only for the following version a commercial one.
    Still pretty uncool, but not completely evil. Building your community thanks to cool "open source" guys and then back-stab them like that is pretty ninja...

    The furious open-users should all delete their posts over their forum. That would be very ninja too =)

  3. that's why you should always look for GNU/GPL type of license when you start to work with some tools... btw strange they forbid to distribute the once "open-source" version (which license was it under?).

  4. @MonkeyOnMyShoulder,

    Your first impression was correct. The 1.4 free edition appears to still be downloadable, but in fact it is not.


    I agree. I also am fine with MIT type permissive licenses, but I certainly would expect that something labeled as "open source" would remain distributable. That doesn't seem to be the case here.

  5. I can't say I'm surprised! I used SIO2 for an iPhone App I developed. I spoke with Romain via Skype when I needed some support. I have to say he was totally unprofessional and just plain rude to me when I gave him my list of questions I needed help with.

    I have been developing commercial software for over 20 years and SIO2 is some of the worst quality/poorly designed software I have ever had the displeasure of using.

  6. That's a ugly move! Not that they made the engine commercial, which is fine! But that they forbid redistribution of the "open" version. There must have been a better way! Obviously they don't understand a thing or two. I find that not very trustworthy, nor intelligent...

  7. @Reece: I had similar experience with the Leadwerks dev (and i'm not alone). Punch in the balls is what you get as support. Lesson learned is that you have to check out the company not just the product.

  8. along with everyone here, i'm confused how further distribution of the originally licensed version is now stopped. for a company to use the allure of 'open source' to get their name out there (for those needing to code, we often look for open source modules on which to build code from, don't reinvent the wheel etc) and then be able to crowd-source usability issues, and for all i know may have even accepted bug-fixes and commits...

    if they wanted to free up a beta preview or something, that would've been fine. if they wanted to commercialize their latest build, hey that's fine too. to deny distribution of something you classified as being 'open' is against the spirit of open.

    there must be some CEO type behind the decision. to imagine any dev consciously making a decision that was so bad for the future palatability of their company is rather shocking. believe me, with any large decent gaming library, they'd have been better off selling documentation, getting started guides, and product support.

  9. It's not there Descision i think, the main reason is that Apple or Microsoft do not allow GPL based Software in there App Stores.

  10. If the software was open source once you don't need the permission of "Romain Marucchi-Foino, head of SIO2" to put the open source version on your website. btw: free is not the same as open source, so you should be sure of course that that version was indeed open source and not just free before you put it on your website.

  11. @Mandrake0,

    Both GameKit and Oolong are actually open source under the MIT license, and both can be used to make iPhone games. I think you're right about GPL though.

  12. I don't have access to the original files so I don't know what was the license. But if it was really open source as defined by the OSI then it must have included the right of free redistribution. So you wouldn't need their permission to redistribute the old version and their would be nothing they could do to prevent you from redistributing it (just be careful that you remove anything that might not be covered by the open source license such as art assets before redistributing).

    If the original license did not include the right to redistribute, then it wasn't open source in the first place and while companies sometimes try to market "source code available with restrictions" as open source, it clearly isn't by the OSI definition and the community should do its best to inform people of the difference.

  13. @Milad Thala,

    For a variety of reasons, that's not possible, fortunately.


    Romain Marucchi-Foino is the copyright holder of the software, and when I asked him directly for permission to make it available, he declined. That's all I know. I'm not a lawyer.

  14. Can they prevent redistribution of the old code? If it's open source then I assumed only updates made by them after the chance were under their copyright.

  15. Spencer Westwood on

    Such a shame.

    I see that the 1.4 software is still downloadable, and as before you need a $50 for a licence to remove the banner etc.. but the game has to keep the source closed

    For the new version they are asking for over $300 licencing fee ... Seems like they've lost their way and don't want to be around for much longer; there's a whole variety of other engines out there for a lot more features at that price - and a lot easier to use (Unity anyone??)

    Whilst its nice to have a Maya exporter it would probably only be useful for converting game assets from larger systems such as PS3/Xbox developers who have probably already solved the problem a different way and have their own engines.

  16. Oh my God , Dammit... I dont Have SI02 !!! I forgot to donwload it after i shifted my New Pc....
    plzzz plzzz Does anyone still own the 1.4 Open source Version ?? I Want that !!!
    Can Anyone Upload it to me ?
    pllll Contact Me on [email protected]

  17. Here is the original "open source" license:

    Generally you can not create commercial applications with GPL software libraries because you have to release all the sourcecode. BUT - a dual licensing system would have worked fine! That would have been a fair option to the users of SIO (especially contributors(!)) and it would have been ok with any publisher.

  18. Tony, will you be updating your book using one of the other truly open source alternatives? I'm currently working on a interactive project that I hope to bring to the Ipad.

  19. I always have mixed feelings about the so called 'open source' that goes so called 'commercial'. Often I feel they benefit from Open Source through patches and so on then take it and 'close' the source.

    Normally I would say FORK! Normal open source licenses cannot take the right given by the license away for the versions released as Open Source.

    Well because of Apple's recent grip on developers and publishers with 30% Apple tax, developing for iOS gets less and less interesting for newcomers and veterans alike. Maybe there will be a better alternative supporting more platforms.

    I do understand that they want to make money of a popular (?) product, but these kind of things make me doubt every 'company' making Open Source software. Before you know it they take it away and all time invested in a product by users is worthless except when buying licenses. But usually they go over the top with license fees that only serious developers will try and able to earn back at least the Apple tax and the licenses used.

    Thanks #Marucchi-Foino

  20. @Riptyde,

    I don't have any plans to update this book. At some point in the future when I have the time I might look into writing about a related technology, although at the moment I'm more interested in investigating Android possibilities.

  21. I've provided that link above but i did not want google to find and improve ranking of the site...
    It is no OSI license but you may call it open source if you get the source (if not all), fix issues, add features and commit the changes. Though it seems it was never in the spirit of open source, it seems he wanted others fix bugs and add features, thats all.

  22. I don´t mind if it is opensource or not, what I´m interested is when will be available in Emule and other free torrent sites to download it free of charge.

  23. It amazes me how few people actually do read and understand the conditions of the licenses of software they use, even developers using these in their own programs.

  24. SIO2 never used an official OSI approved open source license.

    I'm involved as admin in GameKit, Oolong Engine (and Bullet),
    and all of them use exclusively permissive OSI approved licenses such as BSD, MIT and zlib/png,
    so there is no such risk.

    Gamekit has a better and faster Blender asset pipeline than SIO2 and Unity, it reads meshes, textures, skeletal animation, camera, lights, sound and physics data straight from a .blend file.

    You should check it out:

  25. MonkeyOnMyShoulder on

    By the way... today Epic announced that concerning the use of their UDK by indies, the limit for the 25% royalties was raised from $5.000 to $50.000! Before $50.000 of benefits, all incomes to devs... and after, 25% of the "over-50K" benefits for the devs goes to Epic.
    That should be more than enough for a lot of indy devs.
    That's a pretty big move to (probably) try to counter Unity.

    So... where does SIO2 stands in there !? I honestly wouldn't bet much on it in the future as a "professional" middleware.

  26. So SIO2 is inferior to other proprietary solutions such as Unity and Epic UDK.

    None of those proprietary solutions provide the freedom that official approved OSI licensed software,
    such as Oolong Engine and Gamekit provide. I would hope that Blender users appreciate the value of open source.

  27. MonkeyOnMyShoulder on

    Well, like always it's a matter of "who"...

    We all want the best solution for our specific needs, no ? If you're not a developer, want bells & whistles graphics, don't have money upfront, and are quite realistic about the results your game will have... then UDK is indeed a solution you can't ignore. It's free under 50K, proven workflow, technologically at the top, ...
    If you're a dev, want to put your hand in the engine to make up specific features, don't want to get compromised, etc... then it seems logical to go something like Gamekit.

    My 2 cents

  28. Oh, that's too bad :(

    Well, I don't have a Mac, and also, we are working with a Unity3D + Blender pipeline, but for open source developers who really care this matters it's some kind o bad news, isn't?

  29. open-source and android go hand-to-hand. Fuck Apple and Fork SIO if it was indeed under a true open-source license: the original author has no saying on copies obtained under the open-source license terms. He may close from now on, but not close what is already open and in the wild under a legal license.

    we often see things like that happening now and then by people who want to ride the open-source bandwagon without understanding the terms. My latest recollection is the Octane developer wanting to somehow shut down his previous pet project Luxrender, both site and fully GPL'ed sources.

  30. To those that are worried about SIO2 - don't be. Take it from someone who has used it - it really isn't worth the trouble. The true open source alternatives listed here sound like good alternatives. It is extremely unlikely that your game ideas "need" SIO2 to be realised. SIO2 have shown their true nature and you would do well to avoid it like the plague!

  31. Tony,
    Thank you for this noble step.

    My 2 cents are that while using the engine under a license I had to include a pre-compiled library which was supposed to check that I am "legally" using my indie license. This was the case from day one. Using the engine I slowly got the feeling that the SIO2 project is stuck and my first project was also my last.

    With UDK going from 5k to 50k before asking for your money I think its a good choice for professional dev. Mind you, the blender to UDK path is very challenging and there is little being done with it,

    I wish gamekit will get the support it deserves, with wiki, vibrant forums and examples as well as strong dev bases and a roadmap going forward.


  32. @TonyM: Don't take this as criticism, but as advice for the future - When writing a book with "open source" in the (sub) title - make sure all tools the book is about have a OSI approved open license. It's important to educate about what open source is really about.

    It should protect from (or at least limit) damaged cased by others (even poor) business decision - That have failed here :-(

    Hope not to many is hurt.

  33. "I asked Romain Marucchi-Foino, head of SIO2, if it would be possible for Sybex to make the “open source” version (version 1.4) available from the book’s website, but he declined to give me permission to do this."

    Tony, did you mention, how much your book contributed him financially?
    Seems only Tony's book-buyers switched to 'obsolete pages', since there seems to be plenty of choice for a open-source solution...
    I hope Tony wrote it generic enough to still be worth anything to the buyer.

  34. @LaH,

    I totally agree. This was a lesson learned. In the future I intend to be strict about requiring OSI approved licenses before considering anything open source. I was aware that SIO2 used a non-standard license, but I took the developer's claims about being "open source" at face value. This is a great example of what can happen when you do that.

  35. I know and worked with Unity3D on few projects and looking at SIO2's website
    I cannot help myself but feel a stark difference in professionalism here.

    Unity as a commercial product is playing here at a different level.

    In addition links to the free 1.4 after few clicks lead to 1.4 not offered anymore is
    I would plainly say misleading.

    To bad they turned this way but it seems not to be such a loss as well considering
    that there are other good OS solutions there.

  36. Reo: that'd be F-ed up because all the devs that have contributed were never compensated for their works and they claim their source is open source. I certainly hope not -blender's great for everyone -if It weren't for blender/wings/anim8or/gimp ect, I wouldn't be much of a digital artist at all. I salute this great software and the people behind it :) -just hoping nothing like this happens to blender.

  37. Vending

    I know quite many free products which were free during the time they were in development.

    Kerkythea Indigo ...

    It makes sense to give access for free and let users use it for free because you as a developer
    get free feedback as a return and can build a strong community.

    Indigo's user base today is quite big and the product also delivers very good tools/results.

    However SIO2 just looks like bad managed project without the same professional touch
    commercial or open source as others.

    I wouldn't really worry too much. SIO2 is not the only engine.

  38. There should be a free engine available soon which will allow both pc/iphone game development with some really good tools and editors.

  39. I just ordered this book and its in the mail on its Way! In anticipation i downloaded the free version of Si02. Is it completely useless now? Can i still make games for the ipod and will i have to pay royalties? Do the concepts taught in this book help with any other programs like gamekit or is there anything useful to learn now?
    Im ranting im just wondering. =)

  40. Reo: "some voice said Blender 3.0 release will become “Closing” Source….:

    that's not true... GPL will remain GPL. Please do not contribute to FUD. Lot of people could really believe that nonsense

    Free software but not Opensource (Indigo, Kerkythea, Sculptris, SIO2, etc) is different. Blender is Open Source GPL and any work based on it must be released under the same license.

  41. I see this a lot, companies that release a free open-source version to gain a large audience and then switch to a commercial license. Too bad, it won't work...

  42. Don't be afraid! Blender -CAN NEVER- close its source again. It will remain free forever!
    Unless of course Ton Roosendaal gets dictator of the netherlands and declares anarchy! (Possible!)

    But seriously i wonder how little people here understand licenses, especially GPL. Some dont seem to care about licenses but that's because they don't read or understand the meaning of them.

    Erwin Coumans has released most of his work as Zlib license that is the most liberal open source license, his work and belief in collaboration and freedom of software libraries, is a key value to the success and quality his software. The Bullet Physics library has brought enormous benefits to the whole graphics industry and in turn great benefit to the library and Erwin. For some software it is just the right choice - and it is often the right choice to use or get involved in such projects!

  43. “I asked Romain Marucchi-Foino, head of SIO2, if it would be possible for Sybex to make the “open source” version (version 1.4) available from the book’s website, but he declined to give me permission to do this.”

    Open source license don't need permission to be distributed, only usage of the name can be, in some cases, forbidden.

    Anyway, Gamekit/Oolong is first purely open-source but also professional and powerful, it is done for Blender :

  44. The best solution would be if Tony will write open-source-downloadable books, just like the open-source-programmers do! You may even call several books a 'lib' ;)

  45. I notice some people here are discussing the possibility of UDK in their project. Some people (@Shul) have been mentioning that the blender to UDK pipeline is very hard. I find it quite easy. Just follow some tutorials if you have trouble. FBX works great and there is the nice skeletal mesh exporter for your boned objects/characters.

    I say UDK all the way. I didn't use SIO any myself but if former users are annoyed (who wouldn't be, right?) they should band together and boycott SIO. It's not actually a bad trade off with UDK in the bargain.

  46. This discussion forum was really interesting...
    I have learn a lot about Unity3D, UDK licenses and the definition of open source itself.
    I have checked gameKit and wish this is target the android platform.
    Thank all of you for stepping in sharing the knowledge on this matter.

  47. Android made the mistake by making Java its main development platform. You can create C++ libraries and even whole games/applications in C++ now but as far as i know you always need some Java code and JNI bindings. Documentation for C++ on Android is also lacking. Thats why engines can not be ported that easily, though i believe that this will change.

  48. THIS SUCH BULL! Its like they like to take money from people that are creative and can make a sweet living out of it. Everything that has to do with knowledge is EXPENSIVE. 30% tax is a RIP-off and ill never support they're bull. Stay smart and creative people, one day ull be able to use that knowledge to take over that BS. Peace.

  49. FREE SIO2!! FREE SIO2!!! i wish blender would develop an iOS convertor THAT WOULD BE SO EPIC PLEEZE PLEEZE PLEEZE PLEEZE

    i have sio2 but i guess they dont want it online so i guess me posting it is as good as ppl grabbing it from

  50. I had a talk with the so called head of SIO2; he's a complete jerk; it was obvious he was going to do this. Like others have said before check that the software is LGPL not just free before starting to make your life harder by using this kind of software. Fortunately SIO2 will die very soon.

  51. MonkeyOnMyShoulder on

    Honestly, I would love to see all the Blenderers who got involved in helping SIO2 with an Open Source spirit (bug reports, ideas, code, tutorials ...), go to SIO2 forums and edit all their posts to replace them with a common message like "Sorry, but this post is not available for free anymore, please contact support for more information... Viva GPL Revolution !"
    That would make my day! =)

  52. @mav: it doesn't need to be lgpl. Main point is using an OSI approved licence.

    BSD, MIT and Zlib/png are perfectly fine licences, and often preferred over viral licences such as (L)GPL.

    Again, SIO2 never used an OSI approved open source license. Here is the list:

  53. Have to say I read the book which was a very good but, but honestly I was totally unimpressed with SIO. Unity is the way to go, and Blender will still fit into the workflow if you want it to.

  54. @ TonyM

    Consider a copy already sold if you were to publish a book on Creating Games with Blender for Androids. I purchased "3D for iPhone Apps with Blender and SIO2" and found it contained a wealth of knowledge. I look forward to seeing what you produce in the future.

    Best regards,


  55. Anyway, I'd like to mention the Panda3d library here. It's really opensource (BSD lic), uses python (2.x series) which Blender users are usually familiar with, has a great exporter for Blender 2.4x (no more messing with Radiant), has physics engine integrated (Bullet and ODE), and the new 1.7 version has pathfinding (with navmeshes), flocking, steering and other AI behaviours integrated as well. (Actually PandaAI works with 1.6.x Panda as well, but it has to be installed separately. From 1.7 on, it's bundled.)
    Oh, and it has a few commercial games already e.g. Pirates of the Caribbean MMORPG by Disney.

  56. Does anyone have any idea if Sio2 left us with a way to purchase the old license for v1.4? It seems that the URL for the legacy site redirects you to the new site's home page.

  57. Grrrr, there are enough moneygrabbing PITA companies in the world without SIO2 adding to the number. Won't bother downloading their trial version now. Hope the company fails quickly and they learn their lesson.

  58. other alternatives is jmonkeyengine 3.0 , BSD License, has powerful editor, support blender pipeline, easy to use, well and nice community, . and it s going to support android.

  59. Bought this book with great enthusiasm and made my friends aware of this... And now this... I am donating my book to a used book store

  60. If the old version were truly "open source", then they would have NO POWER WHATSOEVER to prevent you from redistributing it. Of course, they may have just billed it as open source while it was really just proprietary freeware. You should have actually READ THE LICENSE before you wrote the book.

  61. iman Hosseini Nia on

    The referenced link (GameKit) is also not a real open source to me since it doesn't let me to view the web page since I am in Iran! why politics should interfere with GNU! I even didn't find a sentence related to the politics!
    Much more than a drug dealer......., GameKit as an open source project sounds bullshit to me.

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