GPL Licensing – Can I Include a GPL v3 Binary with My Proprietary Application if I Prompt the User to Download It at Install Time?

AGPL and GPLv3 were created to close the "GPL as a service" loop hole. If the code is licensed this way and you are going to use the web server in a commercial setting I would look elsewhere.

I am not a lawyer, etc.

Affero General Public License

That is the purpose of the AGPL, am I correct?

AGPL is the opposite of what you are assuming here.

Does this also apply to Javascript frameworks like KendoUI?

You cannot use KendoUI GLPv3 license unless your whole product that is using it is also GPL compatible.

In other words, merely loading a web sites content into my browser is not "conveying" or "distributing" that software.

In GPLv3 and AGPL it is conveying and distributing.

These questions come up time and time again. We can apply logic and reasoning to most of the products in question. Kendo UI has a commercial version of the product available and a GPLv3 version available. It stands to reason that they do not want you using their product in a commercial settings, i.e. a non GPL application, unless you pay for it.

They even spell it out on their web page:

This version is suitable for GPL-compatible open source projects only.

As far as the large majority of open-source licenses is concerned, there is no difference at all between software written in a compiled language (thus providing the ability to distribute object/binary code) and software written in an interpreted language (thus effectively requiring distribution in source form). This also holds for the interaction of these licenses with each other and with non-free licenses.

For example, if you have written a PHP program that makes use of a module that is distributed under the GPL license, then you can not distribute the code you wrote under a license that forbids modification or redistribution. This is regardless of the availability of the source code, because it is about the rights you give the recipients of the program.

To answer your questions: Yes, you can use an LGPL editor in your proprietary application (without affecting the license), provided that the user of the application has the possibility to replace the editor with another (compatible) one. There are no special requirements on how you distribute such an application, but if you use third-party components (regardless of how they are licensed) it is a good idea to clearly identify them in a Readme file or something similar.