Cubes - The Lightweight Python OLAP Framework is now licensed under the MIT license with small addition. The full license is as follows:
Copyright (c) 2011-2012 Stefan Urbanek, see AUTHORS for more details
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
If your version of the Software supports interaction with it remotely through a computer network, the above copyright notice and this permission notice shall be accessible to all users.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
The addition says, that if you use it as part of software as a service (SaaS) you have to provide the copyright notice in an about, legal info, credits or some similar kind of page or info box. That's all.
May it be like that? :-)
Updated Cubes sources are here, as usual.