Re: Why are large code drops damaging to a community?
Large code drops are almost always damaging, since inherent in that process is the concept of "throwing the code over a wall". But sometimes it does work out, assuming that continuity and "good intentions" are followed.
To show this, join me in the Wayback Machine as Sherman and I travel to the year 1995...
This is right around the start of Apache, back when Apache meant the web server, and at the time, the project was basically what was left of the NCSA web server plus some patches and bug fixes... Around this time, one of the core group, Robert Thau, started independent work on a re-architecture of the server, which he code-named "Shambala". It was basically a single contributor effort (himself). One day he simply said to the group, "Here, I have this new design and architecture for Apache. It adds a lot of features." So much of what defines httpd today can find its origin right there: modular framework, pools, preforking (and, as such, the initial gleaming towards MPMs), extendable API, etc...
In many ways, this was a large code drop. What made it different is that there was *support* by the author and the community to work on integrating it into the whole. It became, basically, a community effort.
Now compare that with a different scenario... Once httpd had picked up steam, and making sure that it was ported to everyone's favorite *nix flavor was important, SGI had done work on a set of patches that ported httpd to their OS and provided these patches (a set of 10 very large patch-files, iirc) to the group. What was clear in those patches is that there was no consideration at all on how those patches affected or broke anyone else. They rewrote huge swaths of code, optimizing for SGI and totally destroying any sort of portability for anyone else. And when we responded by, asking for more information, help with chatting with their developers to try to figure things out, and basically trying to figure out how to use and merge this stuff, SGI was basically just silent. They sent it to us and that was the beginning and the end of their involvement as far as they were concerned.
Way, way too many large code drops are the latter. Hardly any are the former.
1. I have paraphrased both the Shambala and SGI events