Add Sōsh data. 0/4 sadly, but being open about this is important.
Adds Webkite, Inc.

Contributor: Greg Gates (software developer at Webkite)
  twitter: @gregates

Source: internal head count
Merge pull request #73 from gregates/patch-1

Update data.txt
Adding Meteor.

Contributor: Matt DeBergalis, founder of Meteor, matt@meteor.com
Source: internal headcount

I'm a founder of Meteor.  We are building a full-stack JavaScript
framework that makes it much faster and easier to write modern apps
where most of the code runs in the browser.

Meteor has 9 full-time technical people.  3 are women.  (Our bios page
is at http://www.meteor.com/about but is running a few people behind.)
Company-wide we are 7 female and 7 male.  And we work hard to promote
balance at Meteor Devshop and at the various Meteor meetups around the
world.  This is super important to us.
Adding Sunrun.

Contributor: Billy Hinners, VP of Technology at Sunrun, billy@sunrun.com
Source: internal headcount

We have 5 full time women programmers with a total current programming
team of 20.  If we add QA, the numbers go to 9 women out of 25.  (I'm
counting two accepted offers in development and one in QA, even though
they don't start for a week or two.  I omitted managers and
contractors completely.)

I'm proud of our numbers, but I'd be even happier if they were higher.

[follow up email message re: QA team]

Well, it's definitely engineering work.  They do a fair bit of writing
automation tests, which is developing software.  But probably only one
of them currently does it enough of that to count as "full time".
That one is a woman though!  Which I guess was obvious since by
looking at the numbers you could rightly deduce that all of our QA
individual contributors are currently women (except the new hire who's
a guy).

So maybe 6 of 21 would be the most accurate count for us right now.
Adding Checkout 51.

Contributor: Rajesh Kumar, Software Developer/Engineer at Checkout
    51. Contact me at @meetrajesh or rajesh@meetrajesh.com
Source: Internal headcount and /about page at
    https://www.checkout51.com/about

Here are the "women in software engineering" numbers for a startup
company I work for in Toronto called "Checkout 51".
Adding MCSI.

Contributor: Anonymous
Source: internal headcount

"Out of 159 devs in the application development team, spread across
multiple countries, I count 21 women"
Adding LaunchBit.

Contributor: Elizabeth Yin, co-founder and CEO of Launchbit, @launchbit
Source: internal headcount

https://twitter.com/launchbit/status/397520404169773056
@triketora ok then our numbers are 1 female engr / 2 total engrs = 50%
Revert "Adding MCSI."

This reverts commit cf603a2400cc47cfb146ea515119728e80843c80.
Add Scientific Learning

Contributor: Dimas Guardado, Principal Engineer at Scientific Learning, @dimasguardado
Source: internal headcount
Adding Stack Exchange

Contributor: Ivete Tecedor, no relation to company, @ivetetecedor

Source: Count of anyone whose title includes the word "developer" on the team page here: http://stackexchange.com/about/team
Merge pull request #77 from itecedor/master

Adding Stack Exchange
Merge pull request #76 from dguardado/scilearn

Add Scientific Learning
Adding HubSpot.

Contributor: Jessica Scott, Tech Lead at HubSpot, @jessbrandi
Source: internal headcount

Includes all full-time Software Engineers (2 women of  49 total) and Tech Leads (2 women of 16 total). Our Tech Leads manage small teams, but still spend the majority of their time coding.
Merge pull request #78 from jessbrandi/master

Adding HubSpot.
Adding Ivycorp.

Contributor: Mary Jesse, Chairman and CEO, Ivycorp, mary@ivycorp.net
Source: internal headcount
Adding creativeLIVE.

Contributor: Anonymous
Source: internal headcount
Adding Circa. Contributor: Michelle Lai, QA & Support Eng. @sparkelle Source: internal headcount. 1/4 strictly dev, 2/5 if you include QA
Submitting Wanelo

Contributor: Sean Flannagan, VP Product, @seanflannagan
Source: Internal headcount
Adding Goodreads

Contributor: Nichole Treadway, Software Engineer at Goodreads, @kntreadway

Source: https://www.goodreads.com/about/team and internal headcount