Simple may refer to:

In technology:

• SIMPLE, a presence and instant messaging protocol suite
• SiMPLE, a programming language
• The Simple algorithm, a numerical method for Computational fluid dynamics

In other uses:

• Simple (abstract algebra), an algebraic structure which in some sense cannot be divided by a smaller structure of the same type
• Simple living or voluntary simplicity, an alternative lifestyle to consumerism
• Simple Shoes, an American shoe brand, a division of Deckers Outdoor Corporation
• Simples, a philosophical concept of objects without parts
• Jesse B. Semple, a character featured in many stories by American writer Langston Hughes
• Simple, a difficulty rating in Dance Dance Revolution
• Simple (Andy Yorke album), an album by English singer-songwriter Andy Yorke

In Stores:

• Simple, a little unofficial food store near Fresno, sells a variety of fruits and other products.

See also

• Simplicity
• Simple English Wikipedia, a version of Wikipedia that uses simpler English language

History

SiMPLE is vaguely reminiscent of the AppleSoft BASIC programming language that existed on the old Apple-II computers. However, instead of being an interpretive language (like most BASICs were), SiMPLE is a compiled language. Furthermore, SiMPLE does not require the use of any line numbers. In addition, SiMPLE allows users to create their own libraries of frequently used functions.

The Three Faces of SiMPLE

(a) Micro-SiMPLE is an introductory programming language designed to use only 4 keywords: Call, Set, If, and Goto. (Other programming languages, such as C++, require the user to know more than 300 keywords.) An example of a Micro-SiMPLE program listing (and a snapshot of the output display it generates) is shown in the figure below:

(b) Pro-SiMPLE is the DOS-based version of SiMPLE requiring the use of only 23 keywords. Its graphics capabilities are limited to only 16 colors with a resolution of only 640 x 480 pixels. Its sound capabilities are limited to simple "beeps" through the computer's built-in speaker. An example of a Pro-SiMPLE program listing (and a snapshot of the output display it generates) is shown in the figure below:

(c) Ultra-SiMPLE is the Windows-based version of SiMPLE. It utilizes exactly the same 23 keywords as Pro-SiMPLE. Its graphics capabilities allow millions of colors in whatever resolution the user's system provides. Its sound capabilities allow the user to play any type of media file (including movies). An example of an Ultra-SiMPLE program listing (and a snapshot of the output display it generates) is shown in the figure below:

Modes of Operation

SiMPLE programs can be run in either "Drag & Drop" mode (intended primarily for beginning programmers), or in "Command-Line" mode (for more advanced programmers):

(a) In "Drag & Drop" mode, the user simply creates a program source listing (a text document), and then runs that program by dragging the source listing document onto a special icon.

(b) In "Command-Line" mode, the user creates and runs programs by typing commands and listings into a DOS window.

The 23 keywords used by SiMPLE are:

SiMPLE requires either Windows 95, 98, Me, 2000, XP, or Vista.

External links

SiMPLE is available as a free download from the SiMPLE Codeworks website

• SiMPLE On-line Tutorial
• SiMPLE Program Gallery
• SiMPLE Forum
• Sheboygan Falls School K12 Programming Course
• Bob Bishop's Homepage

SIMPLE applies SIP to the problems of:

• registering for presence information and receiving notifications when such events occur, for example when a user logs-in or comes back from lunch;
• sending short messages, analogous to SMS or two-way paging;
• managing a session of real-time messages between two or more participants.

Implementations of the SIMPLE based protocols can be found in SIP Softphones and also in SIP Hardphones.

Technical description

Presence

The core protocol machinery. It provides the actual SIP extensions for subscriptions, notifications and publications. RFC 3265 defines the SUBSCRIBE and NOTIFY methods. SUBSCRIBE allows to subscribe to an event on a server, the server responds with NOTIFY, whenever the event come up. RFC 3856 defines, how to make use of SUBSCRIBE/NOTIFY for presence. Two models are defined, an end-to-end model, -each User Agent handles presence subscriptions itself- and a centralized model. The latter introduces the concept of a presence server. All subscriptions are handled by this server. The message PUBLISH (RFC 3903) allows User Agents to inform the presence server about their subscription states.

Presence documents. The presence information is coded in XML documents, that are carried in the bodies of the respective SIP messages. RFC 3863 and RFC 4479 describe this procedure, RFC 4480 (RPID), RFC 4481, RFC 4482 (CPID) and various drafts describe contents and formats of the presence documents.

Privacy, policy and provisioning. If the centralized model is used, the User Agents need a way to define who may subscribe to which amount of their presence information. RFC 4745 and RFC 5025 define a framework for authorization policies controlling access to application-specific data. The XCAP protocol (RFC 4825), carried by HTML, allows User Agents to communicate their presence rules to a XCAP server, who rules the information exposition of the presence server. RFC 3857 and RFC 3858 define a subscription event "watcher info". User Agents may subscribe to this event to be informed, who is subscribing their presence information.

IM

The Page Mode makes use of the SIP method MESSAGE, as defined in RFC 3428. This mode establishes no sessions.

The Session Mode. The Message Session Relay Protocol (RFC 4975, RFC 4976) defines text-based protocol for exchanging arbitrarily sized content of any time between users. An MSRP session is set up by exchanging certain information, such as an MSRP URI, within SIP and SDP signaling.

References