Editing RTML

{{for|the XML dialect for telescope control|Remote Telescope Markup Language}}
[[Image:RTML Linkpath-loop.png|right|thumb|350px|RTML code in the editor]]
'''RTML''' is a [[proprietary programming language]] used exclusively by [[Yahoo!]]'s '''Yahoo! Store''' and '''Yahoo! Site''' [[web hosting service]]s.

==History==
The language originated at [[Viaweb]], a company founded in 1995 by [[Paul Graham (computer programmer)|Paul Graham]] and [[Robert Tappan Morris|Robert T. Morris]], as the template language for their [[electronic commerce|e-commerce]] platform. RTML stands for "Robert T. Morris Language". The RTML editor was offered as an option for customers (usually [[small business]]es) who wanted to customize their [[Online shop|online stores]] more than the built-in templates allowed. The built-in templates were also written in RTML, and provided the starting point for most people who used the language.

In 1998, Yahoo! bought Viaweb for $49.6 million and renamed the service '''Yahoo! Store'''. Yahoo! later offered the RTML-based [[content management system]] in a hosting platform without a [[Shopping cart software|shopping cart]], under the name '''Yahoo! Site'''.<ref>{{cite web |url=http://site.yahoo.com/ |title = Web Hosting Services {{!}} Verizon Small Business Essentials}}</ref>

In 2003, Yahoo! renamed the '''Yahoo! Store''' service '''''Yahoo! Merchant Solutions''''' (part of '''[[Yahoo!#Small business|Yahoo! Small Business]]'''), and at the same time began offering new customers the choice of a more standard [[PHP]]/[[MySQL]] web hosting environment instead of the RTML-based Store Editor. {{As of|2006}}, many new Yahoo! Merchant Solutions sites and legacy Yahoo! Stores continue to be built using the Store Editor and RTML. {{outdated-inline|date=February 2019}}

==Language==
Although Yahoo!'s documentation does not mention it, RTML is actually implemented on top of a [[Lisp programming language|Lisp]]-based system. The language is somewhat unusual in that the programmer cannot edit the source code directly as text. Instead, keywords are presented as [[hyperlink]]s in a [[web browser|browser]]-based [[HTML]] interface. Clicking on a keyword selects it, and its attributes can be edited. Blocks of code can be pushed and popped from a clipboard, using the [[Stack (data structure)|stack metaphor]]. The editor maintains the code's [[s-expression]] structure automatically, and visually represents it in the web interface using [[Indentation (typesetting)|indentation]] instead of Lisp's [[Bracket#Parentheses|parentheses]].
Most of the keywords correspond to [[HTML]] elements, but there are also [[Conditional (programming)|conditional]]s, [[recursion]], and other [[control flow]] features that make it a "real" programming language.

RTML templates are evaluated dynamically for each pageview during editing, but for the live site a "publish" process generates static HTML files from them.

==Abbreviation==
Yahoo!'s documentation used to say that RTML was an [[acronym]] for "Real Time Markup Language", but Graham admitted that "we made up various explanations for what RTML was supposed to stand for, but actually I named it after Robert Morris, the other founder of Viaweb, whose username is rtm."<ref>{{cite web |url=http://lib.store.yahoo.net/lib/paulgraham/bbnexcerpts.txt |access-date=5 Mar 2021 |archive-url=https://archive.today/20210305132755/https://sep.yimg.com/ty/cdn/paulgraham/bbnexcerpts.txt |archive-date=5 Mar 2021 |title=Lisp in Web-Based Applications |date=April 2001}}</ref>

== References ==

{{reflist}}

==External links==
*Yahoo!'s own [https://help.smallbusiness.yahoo.net/s/article/ka21a0000009Y5CAAU/SLN18697 RTML Reference]
*[http://developernetwork.store.yahoo.com Yahoo! Merchant Solutions Developer Network] - Yahoo's Directory of Merchant Solutions Developers
*[http://developer.yahoo.com/stores/index.html Yahoo! Merchant Solutions Developer] site
*[http://paulgraham.com/lwba.html Lisp in Web-Based Applications] - transcript of a talk by Paul Graham that mentions RTML
*[https://smallbusiness.yahoo.com/ Yahoo Small Business] - Yahoo Small Business Official Website

{{Document markup languages}}

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[[Category:Domain-specific programming languages]]
[[Category:Yahoo!]]