GNU GENERAL PUBLIC LICENSE Version 2, June 1991 [2]. In short, this means you are free to use and distribute Inkscape for any purpose, commercial or non-commercial, without any restrictions. You are also free to modify the program as you wish, but with the only restriction that if you distribute the modified version, you must provide access to the source code of the distributed version.
Many developers become involved because they wish to "scratch an itch", so of course if they wish to work on a particular feature, then by definition that one will receive implementational attention. This is the primary mechanism by which features get implemented.
Inkscape also strives to take user requests for features seriously, especially if they're easy to do or mesh with what one of the existing developers already wants to do, or if the user has helped the project in other ways.
If you have a feature that you'd really like to see implemented, but others aren't working on, the right thing to do is delve into the code and develop it yourself. We put great importance on keeping the development process open and straightforward with exactly this in mind.
Inkscape strives to avoid changing the SVG just because it does not recognize some of the SVG elements, however it *does* make changes:
There is ongoing work to allow Inkscape to better preserve hand-created SVG markup but it is a very difficult task requiring a lot of infrastructure work and will happen very gradually - but help is always appreciated.
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