View source for Rio (windowing system)

{{Short description|Windowing system for Plan 9 from Bell Labs}}
{{Multiple issues|
{{third-party|date=August 2015}}
{{more citations needed|date=October 2013}}
}}
{{lowercase|title=rio}}
{{Infobox software
| name                       = rio
| logo                       = 
| screenshot                 = [[Image:Plan 9 Fourth Edition rio interaction screenshot.png|250px|rio interface]]
| caption                    = rio interface as windowing system
| collapsible                = 
| author                     = 
| developer                  = [[Rob Pike]]
| released                   = Fourth Edition / {{Start date and age|2002|04|28}}
| latest release version     = 
| latest release date        = 
| latest preview version     = 
| latest preview date        = 
| frequently updated         = 
| programming language       = [[C (programming language)|C]]
| operating system           = [[Plan 9 from Bell Labs]]
| platform                   = 
| size                       = 
| language                   = 
| status                     = 
| genre                      = [[Windowing system]]
| license                    = 
| website                    = 
}}
'''rio''' is [[Plan 9 from Bell Labs]]' [[windowing system]]. It is well known for making its window management transparent to the application. This allows running rio inside of another window manager.

==History==

rio is the latest in a long series of [[graphical user interface]]s developed at [[Bell Labs]], mostly developed by [[Rob Pike]], the [[concurrent window system]], and the [[Blit (computer terminal)|Blit]] (which predated [[X Window System|X]]).

=== {{frac|8|1|2}} ===
'''''{{frac|8|1|2}}''''' was a [[Windowing system|window system]] developed for the [[Plan 9 from Bell Labs]] [[Operating System|operating system]] by [[Rob Pike]]. According to its documentation, the system has ''little graphical fanciness'', a ''fixed user interface'', and depends on a three-button mouse. Like much of the Plan 9 operating system, many operations work by reading and writing to special files.

Because of the limitations stemming from its unusual implementation, {{frac|8|1|2}} has been [[Rewrite (programming)|completely rewritten]] into its successor [[rio (program)|rio]] in recent Plan 9 versions.

=== rio ===

rio was a [[Rewrite (programming)|complete rewrite]] of [[8½ (Plan 9)|8½]] in [[Alef (programming language)|Alef]]. Its main change was that it stopped parsing and rewriting graphical commands and let the client write pixels directly. This was done mainly for efficiency. As Alef disappeared due to being too difficult to maintain given the number of people working on Plan 9 at the time, rio was rewritten in [[C (programming language)|C]]. This was done using the Plan 9 thread library which was inspired by Alef and had most of its features, such as blocking channels for interthread and interprocess communication. Another important change, due more to the environment than to rio per se, is that rio supports full colour, using [[alpha compositing]], whereas 8½ uses [[Bit blit|bitblt]] operations.

==Design concepts==
Many of its features embody key Plan 9 design concepts:
* Each [[Window (computing)|window]] runs in its own private [[namespace]].
* It exports a [[file system]] interface to running applications. This interface is the same rio receives from the operating system, so rio can run inside a rio window without any special arrangements. Because the interface uses [[9P (protocol)|9P]], rio is [[network transparency|network transparent]] even if it doesn't include any [[Computer networking|network]]-aware code.
* Windows are treated as completely editable text.

==See also==
* [[Plan 9 from Bell Labs]] - rio's native environment
* [[Plan 9 from User Space]] - Includes a window manager that [[emulator|emulates]] the rio user interface
* [[Rob Pike]] - The author of rio and 8½
* [[Blit (computer terminal)|Blit]] - A terminal developed at [[Bell Labs]] that pioneered some of the UI concepts used in Rio.

==External links==
{{commons category}}
*[http://doc.cat-v.org/plan_9/3rd_edition/rio/ Rio: Design of a Concurrent Window System by Rob Pike]
*{{man|1|rio|Plan 9}}
*{{man|4|rio|Plan 9}}
*[http://doc.cat-v.org/plan_9/4th_edition/papers/812/ The 8½ paper] - Describes rio's predecessor which had a very similar design

{{Rob Pike navbox}}

[[Category:2002 software]]
[[Category:Free software programmed in C]]
[[Category:Free windowing systems]]
[[Category:Plan 9 from Bell Labs]]