Hi syman888,

抱歉最近要協力的活動事務較多，拖遲到現在才回覆你的問題。

Q1、TightVNC特別在授權頁面加註「Business-Friendly Licensing」的聲明，是不是表示取用這套軟體在企業內部使用時，必須額外取得該軟體的商業授權才可以使用呢？而UltraVNC並沒有特別加註類似的聲明，是不是表示UltraVNC允許直接佈置在企業內部使用？

簡答：TightVNC和UltraVNC的GPL版本都可以直接佈置在企業內部使用！所差異的僅是tightVNC採取雙重授權的策略，讓不想以GPL方式使用軟體的人，可以額外的向其購置商業授權的版本。

右列為TightVNC的授權說明頁面：https://www.tightvnc.com/licensing.php，裡面說明其「預設」的授權方式就是GPL-2.0的版本，那麼GPL授權的元件，其實並沒有限制使用目的，將其運用在商業公司內部或是打包進商業產品進行販售都是可以的，前提是一併遵守GPL其他的授權規則，最重要的一項授權義務，就是GPL元件的衍生程式，在後續散布上也必須一併以GPL的方式進行授權，也就是說、散布者若是自行有編寫過這個元件，也必須一併釋出這些自行加工編寫的程式源碼(Source Code)才行。

所以說、TightVNC特別標榜其有「Business-Friendly Licensing」的解決方式，這個解決方式其實就是讓不想以GPL方式取得TightVNC的商業公司，能夠另行與其洽詢商業授權的方案，如果一來、依據商業授權版本TightVNC所製造出來的衍生產品，其他部份自行編寫的程式碼，就不會受到GPL授權方式的限制，而必須一併在釋出時提供程式源碼，這是自由開源軟體領域裡常能見到的「雙重授權模式(Dual-licensing Model)。

但是如果您取用TightVNC只是要建置在公司內部使用，而不涉及產品加工與後續散布，那麼原則上直接取用其GPL-2.0授權的版本，便就已經是得到合法授權了！

UltraVNC的狀況更是單純，右列為其下載頁面：https://www.uvnc.com/downloads/ultravnc/95-downlaod-10961.html，授權資訊註明在下載連結的左近，表示UltraVNC就是用GPL來進行授權的，所以運用方式如同上列所說的，單純在公司內部使用、可以直接主張依GPL取得合法授權，而若是沒有後續產品的加值與散布，則亦不生GPL授權拘束性、程式源碼提供義務的相關爭議。

Q2、發現一套軟體「shark007 codecs」，標榜100%免費，那麼使用這套軟體及其所夾附的解碼器，是不是真的可以免費且無侵權之虞的在企業內部安裝使用呢？

初步看過這是一個解碼器的合集與播放框架，其主張解碼器方面、是依據GPL-2.0的授權方式，取自FFmpeg這個專案(This software uses code of FFmpeg licensed under the GPLv2.0)。

所以單純公司內部使用，我個人看法是爭議不大，但是若是要將程式加值到商業產品當中，可能就要評估一下是不是額外要取得解碼器額外的專利授權了！

右列是FFmpeg專案的授權聲明頁面：https://ffmpeg.org/legal.html，就專利的部份、其特別說明FFmpeg專案在撰寫過程中，並沒有去參考別人的技術方法或是做還原破解，但是專利技術的保護範圍，並不是說沒有去參考就必然不會寫出「近似」的技術方法，所以在專利風險上、如果取用這些解碼器是要包裝在商業產品裡的話，最低風險的處理方式，還是建議額外的去取得相關專利的授權。

FFmpeg專案的專利議題說明全文轉錄如下：

Patent Mini-FAQ

A lot of legal questions surrounding patents arise when discussing multimedia technology. This mini-FAQ attempts to address these issues. Note that much of this discussion is based on precedent, or what has happened in the past under similar circumstances. Very little consideration is given to what could happen. If you use your imagination, you can visualize any dire scenario and cease doing any productive work.

Q: Does FFmpeg use patented algorithms?
A: We do not know, we are not lawyers so we are not qualified to answer this. Also we have never read patents to implement any part of FFmpeg, so even if we were qualified we could not answer it as we do not know what is patented. Furthermore the sheer number of software patents makes it impossible to read them all so no one (lawyer or not) could answer such a question with a definite no, those who do lie. What we do know is that various standards FFmpeg supports contain vague hints that any conforming implementation might be subject to some patent rights in some jurisdictions, examples for such statements are:
For H.264:

ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.

And for MPEG-4:

The user's attention is called to the possibility that, for some of the processes specified in this part of ISO/IEC 14496, conformance with this specification may require use of an invention covered by patent rights. By publication of this part of ISO/IEC 14496, no position is taken with respect to the validity of this claim or of any patent rights in connection therewith.

Q: Is it safe to use such patented algorithms?
A: Patent laws vary wildly between jurisdictions, and in many countries patents on algorithms are not recognized. Plus the use of patents to prevent the usage of a format or codec on a specific operating system or together with specific other software might violate antitrust laws. So whether you are safe or not depends on where you live and how judges interpret the law in your jurisdiction.

Q: Bottom line: Should I be worried about patent issues if I use FFmpeg?
A: Are you a private user working with FFmpeg for your own personal purposes? If so, there is remarkably little reason to be concerned. Are you using FFmpeg in a commercial software product? Read on to the next question...

Q: Is it perfectly alright to incorporate the whole FFmpeg core into my own commercial product?
A: You might have a problem here. There have been cases where companies have used FFmpeg in their products. These companies found out that once you start trying to make money from patented technologies, the owners of the patents will come after their licensing fees. Notably, MPEG LA is vigilant and diligent about collecting for MPEG-related technologies.

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希望上述提供的這些資訊對你有所幫助！有後續疑問歡迎隨時接續討論。



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