Wez Furlong wrote:

As Gareth points out, an RRDTool extension is a no-go for the PHP
project due to a licensing conflict.

The best I can suggest is hosting your project on sourceforge.net.

... digging up an old thread, here..
I happened up the rrdtool site, today, and saw this:
http://people.ee.ethz.ch/~oetiker/webtools/rrdtool/license.en.html
"""
If you want to use RRDtool with an opensouce tool that has a GPL
incompatible license, you may be able to get around the problem thanks
to the FLOSS License Exception in the RRDtool license.
"""

The link is, however, broken (his trac is fubar).

Might still be too restrictive (IANAL), but might also be worth a look.
I'd personally like to see a RRDTool extension, as would many others, I
suspect (e.g. the guys at cacti).

"""
FLOSS License Exception

(Adapted from
http://www.mysql.com/company/legal/licensing/foss-exception.html)

I want specified Free/Libre and Open Source Software ("FLOSS")
applications to be able to use specified GPL-licensed RRDtool
libraries (the "Program") despite the fact that not all FLOSS licenses are
compatible with version 2 of the GNU General Public License (the "GPL").

As a special exception to the terms and conditions of version 2.0 of
the GPL:

You are free to distribute a Derivative Work that is formed entirely from
the Program and one or more works (each, a "FLOSS Work") licensed under one
or more of the licenses listed below, as long as:

1. You obey the GPL in all respects for the Program and the Derivative
   Work, except for identifiable sections of the Derivative Work which are
   not derived from the Program, and which can reasonably be considered
   independent and separate works in themselves,

2. all identifiable sections of the Derivative Work which are not derived
   from the Program, and which can reasonably be considered independent and
   separate works in themselves,

   1. are distributed subject to one of the FLOSS licenses listed
      below, and

   2. the object code or executable form of those sections are
      accompanied by the complete corresponding machine-readable source
      code for those sections on the same medium and under the same FLOSS
      license as the corresponding object code or executable forms of
      those sections, and

3. any works which are aggregated with the Program or with a Derivative
   Work on a volume of a storage or distribution medium in accordance with
   the GPL, can reasonably be considered independent and separate works in
   themselves which are not derivatives of either the Program, a Derivative
   Work or a FLOSS Work.

If the above conditions are not met, then the Program may only be copied,
modified, distributed or used under the terms and conditions of the GPL.
"""

S