Is ISC License considered DFSG free?

[Jari Aalto <jari.aalto@cante.net>]

Der Debian legal mailing list members,

The agrep software is currently in non-free. Latest code
appears to have moved under ISC License[1] and I'd like to know
if the code can now be moved to main.

Here is test recorded to SPDX database[2]:

    ISC License:

    Copyright (c) 2004-2010 by Internet Systems Consortium, Inc. ("ISC")
    Copyright (c) 1995-2003 by Internet Software Consortium

    Permission to use, copy, modify, and/or distribute this
    software for any purpose with or without fee is hereby
    granted, provided that the above copyright notice and
    this permission notice appear in all copies.

    THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL
    WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
    EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
    INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
    WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
    TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH
    THE USE OR PERFORMANCE OF THIS SOFTWARE.


Thanks,
Jari

[1] http://webglimpse.net/sublicensing/licensing.html

    (...) Webglimpse and Glimpse are available under the ISC
    open source license (...)

    Anyone distributing the Glimpse code should include the
    following license:

    Copyright 1996, Arizona Board of Regents on behalf of The
    University of Arizona.

    Permission to use, copy, modify, and/or distribute this
    software for any purpose with or without fee is hereby
    granted, provided that the above copyright notice and this
    permission notice appear in all copies.

    THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS
    ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
    EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
    INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
    RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
    ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
    OF THIS SOFTWARE.

[2] https://spdx.org/licenses/ISC