None of this was a serious problem 15 years ago. Today, open source is evolving in the context of such patent scenarios. Software patents are a major motivation for foundations and license evolution. Foundations offer a "liability firewall" that works both ways, protecting patent-holding corporations from community claims on their patents and providing a venue for sheltering from patent attacks. Modern open source licenses such as GPLv3 and MPLv2 offer a "patent peace," granting licenses to contributors' patents in exchange for an agreement not to litigate.
Dealing with software patents is probably easier in the context of open source because there are many eyes to look for prior art, there are many targets for attack so that aggressors are drawn into the open sooner, and there are more minds available to work around patent claims when they are detected. Software patents are thus likely to continue to be a key driver for the evolution of open source, both as communities deal with them and as corporations exploit the benefits of open source foundations and licenses.
Cloud computing has many meanings. It can refer to shared storage accessible via a network, an API to a remote application, a remotely managed VM running a stack of server software, or an application reached via a Web or client app.
Whatever the form, cloud computing's varying instances have shared consequences. First, cloud solutions must be deployed flexibly, especially in load-balancing situations where multiple temporary instances may be required instantaneously. As a result, most proprietary packages, which use complex, metric-based pricing under the assumption that every installation means equal-value use, are unaffordable in cloud applications.
Open source software, on the other hand, is unshackled from the need to obtain or track licenses. It can also be modified to fit your needs. As a consequence, open source software is hugely preferred for delivering the cloud. Moreover, the low cost of getting started with open source software in the cloud means that startup companies overwhelmingly use open source components for the nondifferentiating parts of their business.