On 05 May 2005 17:38:22 -0400
"Nathan J. Williams" <nathanw@wasabisystems.com> wrote:

> There's no contamination from looking at code. Look all you want.

From http://www.opensource.apple.com/apsl/

1.3 "Covered Code" means the Original Code, Modifications, the
combination of Original Code and any Modifications, and/or any
respective portions thereof.

1.4 "Externally Deploy" means: (a) to sublicense, distribute or
otherwise make Covered Code available, directly or indirectly, to anyone
other than You; and/or (b) to use Covered Code, alone or as part of a
Larger Work, in any way to provide a service, including but not limited
to delivery of content, through electronic communication with a client
other than You.

1.5 "Larger Work" means a work which combines Covered Code or portions
thereof with code not governed by the terms of this License.

1.6 "Modifications" mean any addition to, deletion from, and/or change
to, the substance and/or structure of the Original Code, any previous
Modifications, the combination of Original Code and any previous
Modifications, and/or any respective portions thereof. When code is
released as a series of files, a Modification is: (a) any addition to or
deletion from the contents of a file containing Covered Code; and/or (b)
any new file or other representation of computer program statements that
contains any part of Covered Code.

1.7 "Original Code" means (a) the Source Code of a program or other work
as originally made available by Apple under this License, including the
Source Code of any updates or upgrades to such programs or works made
available by Apple under this License, and that has been expressly
identified by Apple as such in the header file(s) of such work; and (b)
the object code compiled from such Source Code and originally made
available by Apple under this License

1.8 "Source Code" means the human readable form of a program or other
work that is suitable for making modifications to it, including all
modules it contains, plus any associated interface definition files,
scripts used to control compilation and installation of an executable
(object code). 

4. Larger Works. You may create a Larger Work by combining Covered Code
with other code not governed by the terms of this License and distribute
the Larger Work as a single product. In each such instance, You must
make sure the requirements of this License are fulfilled for the Covered
Code or any portion thereof.

If you view APSL source code, learn something from a line of code,
modify that line of code to work with the code you have, in order to
make your code work, you have taken Original Code, as defined in 1.7 to
be any part "suitable for modification," and added it to 1.6b, thereby
requiring that the Larger Works, as defined in 1.5, fulfill the
requirements in 4.

There is a danger in looking at non-BSD licensed code, especially
Apple's.

tim