@Moon If you put GNU in the name of your proprietary software program ("open source") and say that it's from GNU, the FSF will rightfully demand you stop doing so if such comes to their notice.
If you put it in the name of some free software, but it is otherwise clear that the software is not related to GNU, GNU may request that you change the name to avoid confusion, but won't force you to do so.
@Moon Then please be sure that you use GPL as the license for the project codes. For example, Gnuboard is not actually affiliated with the GNU project but its license is GPL so people can use Gnuboard just like other GNU software.
However, Gnuplot license actually conflicts with GPL so it can be malicious that if an user expects that Gnuplot's license is GPL like other GNU software, then he will be disappointed or troubled when he find actually it's not.
@tylor Please don't make the assumption that GNU software is always licensed under the "GPL", as there are 3 versions of that license. You can safely make the assumption that all GNU software from the GNU project is free software (sometimes mistakes happen, but such always gets rectified).
A lot of GNU software uses the GPLv3+ or the AGPLv3+, but sometimes other licenses are used when it look like doing so will be tactically better at ensuring freedom.
>Gnuplot license actually conflicts with GPL The gnuplot license is barely a free software license, but it's rather incompatible with all versions of the GPL rather than conflicts with it.
An incompatible license just means that unfortunately you can't combine gnuplot sources with say an GPLv3+'d program and distribute the combination.
Of course, you can still have gnuplot and other GPLv3+'d software on the same filesystem, as in that case there are no derivative works.
@Suiseiseki Your point is completely true and that's what i wanted to say too.
However, the fact that we can't make derivation of Gnuplot is kinda crucial defect when one assumes the program is a part of the GNU project but actually it's not. Because the freedom to make a derivation of the program is one of essential four freedoms that is advocated by many free software activists. At least, every program of GNU fulfills those 4 freedoms.
@tylor >the fact that we can't make derivation of Gnuplot is kinda crucial defect You can make a derivation of gnuplot, otherwise it wouldn't be free software.
You just need to distribute your modifications as patches against the released of source code Gnuplot, which is an annoyance, but you still have freedom 3, as you still can distribute modified versions.
It's a confusing name that the authors shouldn't have chosen, but I can't say anything beyond that.