[logback-user] Why LGPL instead of Apache License?

Ceki Gulcu ceki at qos.ch
Sat Aug 23 14:28:16 CEST 2008

If you are just using logback, then I don't think you have any obligations to 
begin with. The question is then distinguishing between "just using" from 
"extending". If you are accessing logback as a runtime implementation of SLF4J, 
then even under a conservative interpretation of LGPL, you are not linking with 
logback but with SLF4J. It follows that your "work in isolation, is not a 
derivative work of the Library, and therefore falls outside the scope of this 
License [LGPL]."

As I see it, it is pretty clear that you are only "just using" logback and not 
extending it.  Thus, accessing logback via SLF4J limits LGPL's protective (or 
viral depending on your point of view) properties so that it does not propagate 
to your application.

I hope this answers your question,

cowwoc wrote:
> If my application is written against slf4j but I plug in logback at runtime
> as the logging implementation doesn't this somehow imply that my application
> is linking against logback and as such the LGPL applies?
> Gili

Ceki Gülcü

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