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From Peter Elst <>
Subject Re: [PROPOSAL] Flex for Apache Incubator
Date Thu, 22 Dec 2011 10:28:03 GMT
I think you do make a good point Raju and one that has been a discussion
topic in our community to some extent but is in my opinion certainly not a

Speaking as a committer - and my feeling is most of us would subscribe to
this - having Flex export as SWF run on the Adobe Flash Player is the
current situation and will get evaluated as needed, possibly looking at
multiple export formats or open source runtime alternatives if the need is

Those projects - if they happen - are huge efforts and I don't particularly
see it fit into the scope of the current Apache Flex proposal.

As far as I am aware Tamarin / AVM2 is compatible with everything AS3
onwards including Flex.

- Peter

On Thu, Dec 22, 2011 at 10:04 AM, Raju Bitter <>wrote:

> Leo,
> I agree with you that Flex is different in that it's targeting a
> proprietary VM. That's why I think it should be a goal of Apache Flex
> to create an alternative runtime, next to Flash/AIR, and it should be
> part of the proposal. Since I'm not an ASF member, I can just hint to
> it, it's up to the ASF members to make that decision.
> But I still think not everyone is aware of what "Flex" really means,
> and which products/standards/trademarks are related to it:
> What is Flex? Flex creates files which run in Flash Player
> Ted Patrick, one of the former platform evangelist working for Adobe,
> had a good post on Flex back in 2008, titled "What is Flex?"
> "At the heart of Flex is the ability to create SWF files that run in
> Adobe Flash Player. Distill all the features down and really it is a
> development paradigm that compiles to SWF."
> The importance of ActionScript for Flex
> I would say that the key components of Flex as a technology stack -
> with regards to Apache Flex - are:
> 1) Flex ActionScript and MXML compiler
> 2) ActionScript programming language and standard
> 3) ActionScript bytecode format SWF
> 3) ActionScript Virtual Machine 2 (in Flash Player and Adobe AIR runtime)
> With the current proposal, the ActionScript and MXML compiler would be
> part of Apache Flex. But what about the rest of the key ingredients:
> ActionScript
> Adobe has a trademark on ActionScript. The Mozilla Tamarin page says:
> "ActionScript™ is the name used for Adobe's implementation of the
> language specification. Adobe is in the process of developing a
> licensing program that will allow developers, whose code passes a
> designated test suite, to say that their application or implementation
> is ActionScript-compliant." If that is still valid, it means that an
> open source implementation of an ActionScript would have to be
> licensed by Adobe to be compliant.
> ActionScript itself doesn't seem to have a license attached to it (I
> could not find any information).
> All MXML code in Flex is first being compiled into ActionScript 3, and
> the compiled into an SWF file, or binary libraries. Therefore
> ActionScript 3 is the single core language of Flex. Since there is
> nothing said in the Apache Flex proposal about ActionScript 3, I would
> say that Adobe maintains the right to change ActionScript at any point
> in time, and that Adobe will still own the ActionScript trademark.
> ActionScript Bytecode Format (SWF)
> SWF is an open spefication:
> "The SWF file format is available as an open specification to create
> products and technology that implement the specification."
> The SWF format for the ActionScript Virtual Machine 2 can be found
> here, there's a copyright on the spec:
> "Copyright © 2006-2008 Adobe Systems Incorporated. All rights
> reserved. This manual may not be copied, photocopied, reproduced,
> translated, or converted to any electronic or machine-readable form in
> whole or in part without written approval from Adobe Systems
> Incorporated."
> Changes to the SWF bytecode format
> That means, the SWF standard is not binding, an Adobe could change the
> SWF format without notice at any point in time. For Apache Flex that
> would mean, Adobe would legally not have to notify Apache of changes
> to the SWF format.
> SWF versions
> Each major player release introduces a new version of SWF (normally
> adding some APIs, e.g. enhanced text rendering with the Text Layout
> Framework in Flash Player 10, native JSON support in Flash Player 11).
> The SWF specification carries the version number 10, it's not clear if
> there is a document available for the SWF 11 specification.
> The AVM2 (Flash Player or Adobe AIR)
> Adobe provides an overview document for the AVM2 at
> The Flash Player and AIR support proprietary technologies which are
> built into the player, and accessible out of Flex applications. One of
> the those technologies is included in the RTMP implementation of Flash
> Player (encrypted Real Time Media Protocol RTMPE). The RTMP protocol
> specification has been published by Adobe, but RTMPE not.
> "By downloading the RTMP specification, you are agreeing to the RTMP
> license. To benefit customers who want to protect their content, the
> open RTMP specification does not include Adobe's unique secure RTMP
> measures, nor does the license that accompanies the specification
> allow developers to circumvent such measures."
> Again, I'm in favor of an Apache Flex project, but based on this
> information I would suggest to find answers to the following
> questions:
> 1) ActionScript
>  a) Is it acceptable for Apache to have Adobe own the ActionScript
> trademark? What does that mean for Apache Flex?
>  b) If the Apache Flex project would create an open source
> ActionScript VM, it seems that would have to be licensed by Adobe?
>  c) Is it acceptable for Apache if Adobe can change the ActionScript
> language without approval from Apache Flex?
> 2) SWF / ActionScript Bytecode
>  a) The current version of Flash Player is The SWF
> specification only covers SWF10, not SWF11. Does Adobe have an updated
> version of that specification, and would Apache Flex have access to
> it?
>  b) If the SWF format is the only format supported by Adobe Flex, is
> it acceptable for Apache if Adobe can change the format without
> notice?
> 3) ActionScript Virtual Machine
>  a) Since there seems to be no open source implementation of the
> current AVM available (question: is Tamarin still compatible with the
> Flash Player AVM2?), a future decision of Adobe to discontinue Flash
> would leave Apache Flex without a runtime environment. Is that
> acceptable, or would it be useful to have an agreement that in such a
> case Apache would be given access to the latest AVM source code by
> Adobe (to be clear: not Flash Player, just the AVM built into Flash
> Player). That would enable the Apache community to develop an SWF AVM
> on its own.
> I know this message is very long, but I think these topics need some
> clarification.
> Raju
> 2011/12/21 Leo Simons <>:
> > Hey folks,
> >
> > I had to think about this a bunch. We don't have anything like this at
> > apache today.
> >
> > On Tue, Dec 20, 2011 at 9:37 PM, Greg Stein <> wrote:
> >> On Tue, Dec 20, 2011 at 15:30, Raju Bitter <>
> wrote:
> >>> (..) Adobe Flex is quite different from most Apache projects (...)
> >>> it looks like the output of the compiler can only be used with
> Adobe-owned
> >>> proprietary software at the moment. (...)
> >>
> >> As I mentioned above, I don't see this as a problem whatsoever. (...)
> >
> > Just to pick this apart...
> >
> > * Flex helps you make apps that target the flash player (or the AIR
> runtime...)
> > * There is effectively one implementation of flash player (supporting
> > the v10 SWFs that come out of flex...)
> > ** which you get from adobe or someone that has an agreement with adobe
> > ** which comes with very restrictive licenses [3]
> > *** basically you probably can't even *use* it if you want to
> > implement a flash player yourself [4].
> > * This flash player plays SWF files (and FLVs..).
> > ** SWF has an "open spec" that isn't very open at all [1,2].
> > * Flex does not produce SWF files all by itself. It uses the Flash SDK
> > and the AIR SDK (and some other bits)
> > ** which you have to get from adobe and which come with very
> > restrictive licenses.
> > * Adobe could unilaterally change the license for the flash player,
> > the SWF format, and/or the prerequisite SDKs, and flex would become
> > essentially useless.
> >
> > Analogies to .Net or Java (or oracle databases) don't make much sense
> > to me. Instead if I had to come up with an analogy, it would be
> > something like having an apache http server that you could only
> > install on windows, and run only if you already had IIS, and that
> > would then host websites that you could only view if you had internet
> > explorer.
> >
> > I don't understand why it's useful to have such a project at apache.
> > But, apparently, a lot of people do want to work on it, and flex is
> > obviously useful to a lot of people.
> >
> > So is there a problem? I guess not. As long as the Apache Flex website
> > makes all this clear enough and no-one makes a PR mess out of it or
> > anything like that, I don't see any actual problem with the proposal.
> > I can't say I'm enthusiastic about it, but I don't have to be.
> >
> >
> > cheerio,
> >
> >
> > Leo
> >
> > [1]
> > [2]
> > [3]
> > [4]
> >
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