Why did we drop GPL for our Windows Phone 7 (WP7) charting controls?


We are proud of our controls. If you had ever thought of using charts in Silverlight or WPF you could have hardly missed us. We were open source & gave away controls for free. Later introduced a commercial license to support the development costs. There was hardly any difference between the free & commercial license. Our objective was just to support the development costs & continue giving away things back to the community. Of course, we reaped benefits of being open source. The product was tested by the large community. Enterprise users happily paid for using rock-solid product. We were doing good – hundreds of thousands of users & hundreds of customers.

And there came Windows Phone 7 (WP7). WP7 applications were to be written in Silverlight. We soon released WP7 charts. Everyone was happy. Soon started the GPL & WP7 Marketplace confusion. We started to feel the heat – our help desk was inundated with queries from users who were not sure if they could use Visifire in their applications. Lost several customers to “commercial only” competitors. One couldn’t have used Visifire in WP7 applications as it is GPLed. Microsoft has explicitly mentioned GPL in the excluded license. Refer: Section 1.l & 5.e of Windows Marketplace Application Provider Agreement. With Microsoft partnering with Nokia the space could only get bigger & better. We could no longer continue losing users & customers. We succumbed & dropped GPL!

Team Visifire


  1. February 18th, 2011 | 12:59 pm

    [...] This post was mentioned on Twitter by Team Visifire, HN Firehose. HN Firehose said: Why did we drop GPL for our Windows Phone 7 (WP7) charting controls?: http://bit.ly/gchKTh [...]

  2. February 20th, 2011 | 6:10 am

    [...] sourced software may not be distributed by the WP7 marketplace (which caused several developers to change their licensing models). But Microsoft and Apple’s prohibition comes from ignorance in regarding to the licenses [...]

  3. February 21st, 2011 | 10:04 pm

    Stupid question, but were you GPL2 or GPL3…

    there’s NOTHING wrong with GPL2 under the Microsoft licensing terms — it’s all the same stuff that made linus reject GPL3 for linux that is making microsoft reject it for their store.

  4. Chirag
    February 22nd, 2011 | 1:27 am


    You are right. We were GPLv3. But I disagree that GPLv2 is OK at Marketplace. Although Microsoft has excluded GPLv3 explicitly, it does this only by way of example. Let me paste the excerpt from Marketplace Agreement.

    “Excluded License” means any license requiring, as a condition of use, modification and/or distribution of the software subject to the license, that the software or other software combined and/or distributed with it be

    (i) disclosed or distributed in source code form;
    (ii) licensed for the purpose of making derivative works; or
    (iii) redistributable at no charge.

    Excluded Licenses include, but are not limited to the GPLv3 Licenses. For the purpose of this definition, “GPLv3 Licenses” means the GNU General Public License version 3, the GNU Affero General Public License version 3, the GNU Lesser General Public License version 3, and any equivalents to the foregoing.

    It clearly states that the exclusion is not limited to GPLv3. In fact, GPLv2 also necessitates one to disclose source code and create derivative works. Hence it is disallowed too. Please let me know if I’m missing something.


  5. February 25th, 2011 | 7:37 pm

    No worries here. Your commercial license is well worth the price to make our WP7 application great.

  6. February 28th, 2011 | 3:42 am


    Thanks for the nice words!


  7. March 15th, 2011 | 8:57 am

    [...] יכולות להיות מופצות באמצעות השוק (מה שגרם למספר מפתחים לשנות את מודל הרישוי שלהם). אלא שהאיסור של מיקרוסופט ושל אפל נובע מבורות [...]

  8. March 16th, 2011 | 3:01 am

    [...] להיות מופצות באמצעות השוק (מה שגרם למספר מפתחים לשנות את מודל הרישוי שלהם). אלא שהאיסור של מיקרוסופט ושל אפל נובע מבורות [...]

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