License Clarification

[mkfs]

This is not an actual issue, but a request for additional information that should, ultimately, be searchable by the public.

The license file https://raw.github.com/mbostock/d3/master/LICENSE contains a pretty stock license for standard applications and libraries, but it's a bit confusing when applied to web applications.

When hosting the d3 package, a server "redistributes" it in source code form to a browser client, so condition 1) should apply.

This defeats (to some extent) the purpose of using the minimized/uglified versions of the javascript code. If these were treated as "binary redistribution", then condition 2) should apply.

In this case, however, the copyright notice is buried in a documentation file that may not ever be accessed by the end user, which seems a disservice.

What is the recommended way to incorporate d3 into a proprietary/commercial/non-open web application? Would it suffice to include the copyright notice and a link to the license file (or a copy thereof) as an HTML comment in the pages that use d3?

[mbostock]

There are very different answers as to what I prefer and what the license legally requires.

From a practical standpoint, your users won't read HTML or JavaScript comments. My preference, then, is visible attribution on the page itself (e.g., "Built with D3") and a link to D3. This needn't be anything prominent, and could be relegated to some obscure documentation page or blog post describing your product, but anything and everything is appreciated. In my view, it's simply considerate to acknowledge the open-source technologies that went into your product. This acknowledgement shouldn't be a burden, though.

From a legal standpoint, the license says only that you must reproduce the copyright notice and the license itself. I am not a lawyer, so I can't tell you exactly how you should interpret it. I know that the vast majority of open-source JS libraries include the copyright or license as a comment in the JavaScript file itself. If you want to do that, too, that would satisfy the license in my understanding. But, something an end-user can see without view-source would be valued much more.

[mkfs]

OK, that clears things up. Thanks.

[ywarnier]

Note to self: this is a 3-clause revised BSD license: https://en.wikipedia.org/wiki/BSD_licenses#3-clause_license_.28.22Revised_BSD_License.22.2C_.22New_BSD_License.22.2C_or_.22Modified_BSD_License.22.29

[teetotum]

We are using D3 in our product. Thanks for making your work available as open source.

Two weeks ago, as I was authoring an entry about third-party-software for our documentation I tried to find out in which category of established open software licenses your license falls.
Identified it (erroneously) as a modified Apache Software License, version 1.1 (the modification would be: deletion of conditions #3 and #5 of the original Apache Software License,Version 1.1, http://www.apache.org/licenses/LICENSE-1.1).

Today I found out (by pure luck) it really is a 3-clause BSD license.

There might be others like me (not really well versed in license stuff) scratching their heads whether this is a MIT license, or something else. Please consider to add a hint that the license is the 3-clause BSD. Again many thanks for a great lib.