Anton Tagunov wrote: Anton> On one account I understand that a commercial company Anton> can create derived work even from GPL works as long as Anton> the result is used only for its internal needs Anton> and distributed. From the aspect I'm okay even with GPL. Anton> Correction: I meant and NOT distributed. Anton> This is a typical case for where I work at. True. I might add that relatively few people know that GPL is non-viral when the hosting software (using GPLed code) is used only internally and NOT distributed. Anton> And this is where my concerns chime in. I'm really really Anton> concerned that to beat Log4J SLF4J/Logback need to beat it Anton> on all fronts. Including the license. Anton> That was the essence of my opinion: SLF4J/Logback are great and Anton> deserve to win. In order to win they need to win the hearts of Big Anton> Co-s to. And to do so they need MIT/ASL. The various open-source licenses have their pros and cons. I agree with you that LGPL might hinder adoption within the ASF and beyond. As a counter-example, one could mention Hibernate which totally dominates the ORM market. More to the point, Java 7 is distributed under GPL+"classpath exception". When it is officially released and users start to adopt it in very large numbers, then whatever opposition against GPL/LGPL is likely to wither away. As for loggback's license, we have no irrepressible urge to dominate the "world of logging". If we do, that would be cool, if we don't, we don't. Nevertheless, your arguments make sense, and logback's license may be changed depending on how the future unfolds.