Can I use logos from vendors in my open-source project?
<p>I have an <a href="https://en.wikipedia.org/wiki/Open-source_software" rel="nofollow noreferrer">open-source</a> project that is quite popular with dozens of downloads per day. I use logos from big companies in there (e.g. Cisco or Microsoft) to customize some web pages. The logos are important for the project's effectiveness.</p>

<p>Can I use these logos under "fair use" considering that I'm not making any money out of the open-source project? It's worth mentioning that I'm confident that users of the project are using it for commercial uses (e.g. to sell their services).</p>

<p>Generally you can only use logos (i.e., symbolic trademarks) if you have the trademark owners' permission. You may certainly use the names Cisco and Microsoft nominatively, although they might ask you to provide a disclaimer of any affiliation including sponsorhip or approval, if it gets to them.  "Not making any money" is also not the sole determinative factor in proving your defense of "fair use".</p>

software trademark fair-use