25 Women in 10 Free Software Organizations for GNOME's Outreach Program for Women

No that is irrelevant... just because woman can easily get _a_ golf course membership somewhere, does not means that Augusta is not discriminating against women.

"The program would be discriminating against men if men had any trouble joining open source projects. Looking at the ratio, they don't. "

The ratio of selected candidate does not prove anything.
Analyzing the ratio of lottery winners does not tell you anything about how easy it is to win the lottery...
(and before retorting that only men win, bear in mind that in that case the ratio of winners is identical the the ratio of players... and sure people that did not buy a lottery ticket did not win... not a big surprise)

"Most certainly the ratio of women in open source projects doesn't match the ratio of women in computer science programs"

So?
I would suggest you establish the ratio of student of computer science programs, based on their primary motivation for choosing that field.
There would be 2 main categories: the one that do that because they are passionate about the field and the one that do that because there is a good prospect of career, better than architect or Mechanical Engineering or any other field that they would have been capable of graduating from.

In the past 20 years I've noticed that the proportion of job candidates that are in the field just to pay the bills are growing significantly, being now-a-days a large majority. That does not means they are not good at their job, but that means that if it was not for a pay check they would certainly do something else...
and in my experience, that category is about 50/50 male/female.
Now, considering that Volunteering is usually not a gainful position, and certainly not the easiest way to get a full time pay job in IT, that subgroup of computer software student is very largely under-represented in Open Source software volunteer ranks.

So, the raw juxtaposition of the gender ration among 'computer science program students' and 'open source volunteers' is not very indicative at all. It certainly do not make the case for 'open-source project 'discriminate' against women.

I would also note that, Open source is a rare field of endeavor that 1/ is mostly volunteer based: you don't get hired, you don't get drafted... you just show-up.
2/ a lot of the interactions are not in-person. When I review a patch posted to the ML, I certainly can't tell the gender of the author, nor do I care. And certainly if someone were rejecting patch based on the perceived gender, or nationality, or creed or ... I'd be there to object.
But my objection would be on the ground of 'irrelevant' criteria... and that is a two ways street.
3/ it is a very recent human endeavor, that attracted a section of the population that is much more liberal and progressive than the general population.

all these tend to indicate that open-source communities are actually less likely to discriminate based on gender than the general population.

"Seriously, go back to the MRA hole you came from"
Is that supposed to be an example of courteous, friendly atmosphere that one is exhorted to cultivate in open-source project ?
Just because I disagree whit the notion that two wrongs make a right, you must resort to name-calling ?

I any case, we are digressing quite a bit from the core objection I have:
Job discrimination is morally wrong, not matter who discriminate against whom. two wrong do not make a right, and are on the contrary more likely to create even more conflict and animosity.
I leave you with this quote from 'The West Wing' that illustrate the failure of such policy to resolve anything:

http://www.youtube.com/watch?v=9YjoSMwVOXQ