Request for Legacy Approval for the LaTeX Project Public Licence

[Will Robertson]

Hi Bruce,

Thanks for your quick reply.

On 09/09/2009, at 8:51 AM, Bruce Perens wrote:

> I've never really had to flowchart a license. Until now. It's pretty  
> complicated for what it does.


[And the Apache licence is more complicated than the BSD/MIT licences  
for little difference in end result :)]

The LPPL arose in order to protect the stability of documents typeset  
with LaTeX. The team did not want it to be possible for distribution  
of modified versions of code that did not identify themselves as such  
in case peoples documents unexpectedly changed, or worse, broke due to  
a component of the system that managed to get itself unofficially  
"improved".

The distinction between "work" and "compiled work" arose due to the  
nature of how software is distributed for LaTeX. Plain text sources  
with comments are "compiled" to produce plain text input files for the  
formatter. Thus, modified compiled works are just as easy to  
distribute as modified sources.

The idea behind "Maintenance of the work" is that, for reasons similar  
to the above, old code that is no longer maintained goes into limbo  
and cannot be updated without some sort of mechanism in place to  
ensure the changes made are suitable and can be traced back to  
someone. (I can't just submit a patch to someone else's package on  
CTAN, for example. The CTAN people won't let me -- how do they know I  
know what I'm doing? However, I can submit a patched version of a  
package under a different name.)

But all of that is by-the-by in terms of what you can do with software  
distributed under the licence: freely use and redistribute, and the  
only restriction on modification+redistribution is that the name of  
the code needs to be changed (or some other suitable manner of  
alerting the user that this is not the original software), unless you  
want to become the official maintainer of the code. The flowchart- 
requiring details of the licence simply formalises this.

Will