I might do this. It might be at http://sagenb.com (right now sagenb.com points to sagenb.org). Here's the "business plan". Probably, sagenb.com would appear almost the same as sagenb.org, except there would be Google (?) ads on the side of your worksheets, and the revenue would go toward paying for:

**Commercial server hosting:**Some Amazon EC2 instances**An employee (or later, employees) to maintain the servers:**at the beginning, this would be me in my free time, since I have a lot of experience with this.**Advertising that sagenb.com exists and we want users!:**Unlike sagenb.org, we would very strongly encourage as many people as possible to use sagenb.com. The advertising and landing page would explain that though sagenb.com generates money, all that money is all given back to the Sage development community (see below).**Hire employees to improve the notebook:**Fix bugs, implement features, etc. There would be a public commitment that*all*such work would be open sourced and get included with Sage. This would include adding support for a for-pay "pro" subscription version, adding nicer "offline support" (via a Sage install on the user's computer), integrated spreadsheets and better data visualization and manipulation tools for Science and business applications, and enabling development of Sage's core library and patches submission entirely through the notebook, etc.

At some point, there could be a $X/year subscription version that would remove all ads, and increase disk space available to that user. There would also be a $Y/year university site license version with customized authentication (e.g., LDAP?) for each university. The university site license version might also include Maple/Mathematica/Matlab/Magma pre-installed in their notebook server, assuming appropriate site licenses are honored, so sagenb.com could be something that goes beyond just a platform for "sage as math software". We can of course also tap into the R market, given that Sage includes R.

I imagine the above being done as a not-for-profit effort, so if it brought in a lot of revenue (e.g., more than needed for hosting and employees), excess money would go to the Sage Foundation to support other Sage development activities. Regarding numbers, according to Google Analytics, right now on average well over 1000 people use sagenb.org every day. Standard commercial hosting costs for EC2 to support this load would be roughly $100/month. If each visitor generates on average of 1 penny of ad revenue per day (is this a reasonable estimate -- I have no clue?), then we would expect to make $3,650 in one year, which would be enough to fund the EC2 service (at about $2000/year), with a profit of $1,650.

Now let's dream big! There might be 1,000,000 potential daily users out there for a service like this, if it worked sufficiently well, since there are many college students (and people that use math and stats programs like R in the sciences, and R is part of Sage) in the world. Scaling up by a factor of 1,000 would yield over $1 million/year, after paying for hosting fees. This would be enough to fund substantial work to improve Sage, the notebook, and have a paid Patch Editor position (imagine buying out a top Sage developer professor, e.g., John Palmierri, from 50% of his teaching obligations in exchange for him spending the time he would spend teaching instead organizing that the patches to Sage get properly refereed). Maybe we could even hire back some of the (many!) people who were Sage developers when they were mathematics grad student or postdocs, but who then went to work at a top web technology company and acquired useful experience there (and are now way too busy to work on Sage).

This has the potential to make Sage a more longterm self-sustaining project. It's probably not possible to get traditional venture capital for a not-for-profit plan like the one above, but fortunately that is not needed due to (1) the generous support the National Science Foundation is currently providing toward development on the Sage notebook, and (2) private donations to the Sage Foundation. In particular, (2) provides enough money to bootstrap a sagenb.com for a while.

I think the main potential downside is competition. If somebody else does the same thing right now for profit without giving back their changes, and captures the market it's hard to imagine how the above would work. Since we don't use the Affero GPL for the Sage notebook, it is legal for somebody to do a lot of customization work to Sage and notebook, create a web-app using this customized version, and give back nothing to the community, so long as they don't redistribute their modified versions publicly. This isn't crazy -- not so long ago, I had a major company (I won't say who out of respect) tell me they planed to do something like that. And "random people" suggest it somewhat regularly when I give talks about Sage. I'm surprised it hasn't happened yet, but it definitely hasn't.

So the time to do this is today. The notebook software we have is now finally reasonably scalable, primarily due to work of Mike Hansen and Rado Kirov. Our funding situation is good

**. We have strong good will and interest right now from both the Mathematical Association of America and WebWork developers. If we wait longer, the one chance to truly make Sage financially self-sustaining in a way that fits with my dreams and values will pass.**

*this year*I hope that by making all plans open, and by having a commitment to put the profits back into Sage development, an enterprise like I describe here will be in a better position to attract users than a purely for profit venture by somebody else.