Harold Hallikainen hallikainen.org> writes: > Interesting discussion! If you produce an embedded system product that > has, say, a custom application running on a GPL operating system or making > calls to GPL libraries, how much source code must you release? Do you need > to release the source code of the custom application, or just the open > source stuff that you are including unmodified? In theory, if you aggregate only with LGPL libraries then you can release a just a relinkable module. The Linux kernel itself is legal to use (i.e. you can run your applications on it) as long as you do not modify it. If you link to GPL libraries then you have to release the entire source. But, in a typical embedded system with control from a host the embedded code need not be released at all (assuming it was not linked against anything GPL). The result is that many times third party developers develop their own front ends to 'your' embedded system. This is usually good, not bad imho. Several PIC development tools went that way (e.g. the recent discussion here about pickit2 drivers on Linux and FreeBSD). You don't *have* to use Linux at all. I personally prefer to use NetBSD for controlling hosts (BSD license from A to Z - well, almost). So basically if the smarts are in the embedded system, they stay protected until they are valuable enough to be emulated 100% or read out of the chips by a cracker company. At least, this is my take. Peter -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist