The United States Department of Defense (DoD) has published the document "Clarifying Guidance Regarding Open Source Software".
The content of this document is particularly interesting:
There are positive aspects of OSS that should be considered when conducting market research on software for DoD use, such as:
(i) The continuous and broad peer-review enabled by publicly available source code supports software reliability and security efforts through the identification and elimination of defects that might otherwise go unrecognized by a more limited core development team.
(ii) The unrestricted ability to modify software source code enables the Department to respond more rapidly to changing situations, missions, and future threats.
(iii) Reliance on a particular software developer or vendor due to proprietary restrictions may be reduced by the use of OSS, which can be operated and maintained by multiple vendors, thus reducing barriers to entry and exit.
(iv) Open source licenses do not restrict who can use the software or the fields of endeavor in which the software can be used. Therefore, OSS provides a net-centric licensing model that enables rapid provisioning of both known and unanticipated users.
(v) Since OSS typically does not have a per-seat licensing cost, it can provide a cost advantage in situations where many copies of the software may be required, and can mitigate risk of cost growth due to licensing in situations where the total number of users may not be known in advance.
(vi) By sharing the responsibility for maintenance of OSS with other users, the Department can benefit by reducing the total cost of ownership for software, particularly compared with software for which the Department has sole responsibility for maintenance.
(vii) OSS is particularly suitable for rapid prototyping and experimentation, where the ability to “test drive” the software with minimal costs and administrative delays can be important.
If features are equivalent, do you still see advantage to use proprietary software ?