TeeChart is a Charting Library for programmers developed and managed by Steema Software of Girona, Catalonia, Spain. It is available as commercial and non-commercial software. Borland (later handing on the IDE business to Embarcadero Technologies) has included a standard version of TeeChart as an integral part of the toolbox palette in most Borland Delphi and C++ Builder Integrated development environment (IDEs) since 1997 and TeeChart currently forms a part of Embarcadero RAD Studio XE5. TeeChart Pro version is a commercial product that offers shareware releases for all of its formats, TeeChart.Lite for .NET is a free charting component for the Microsoft Visual Studio .NET community and TeeChart for PHP is an open-source library for PHP environments. The TeeChart Charting Library offers Charts, Maps and Gauge (instrument) in versions for Delphi VCL and FireMonkey (FMX), Activex, C Sharp (programming language) for Microsoft Visual Studio .NET, Java (programming language) and PHP. Full sourcecode has always been available for all versions except the ActiveX version. TeeChart's user interface is translated to 37 languages.
TAChart, a similar open-source implementation, is bundled with the LCL of the Lazarus IDE. TAChart is not intended to be a TChart clone, therefore its usage differs in certain points, although its basic functionality is very similar and some source code written for TeeChart may be reused.
The first version of TeeChart was authored in 1995 by David Berneda, co-founder of Steema, using the Borland Delphi Visual Component Library programming environment and TeeChart was first released as a shareware version and made available via Compuserve in the same year. It was written in the first version of Delphi VCL, as a 16-bit Charting Library named TeeChart version 1. The next version of TeeChart was released as a 32-bit library (Delphi 2 supported 32-bit compilation) but was badged as TeeChart VCL v3 to coincide with Borland's naming convention for inclusion on the toolbox palette of Borland Delphi v3 in 1997 and with C++ Builder v3 in 1998. It has been on the Delphi/C++ Builder toolbox palette ever since, current version being Embarcadero RAD Studio XE5.
TeeChart is a general purpose charting component designed for use in differing ambits, offering a wide range of aesthetics to chart data. Generally TeeCharts published in the field, in areas where large amounts of data must be interpreted regularly, remain by designer choice in their simplest form to maximize the "data-ink ratio". Sloan Digital Sky Survey, SDSS Web Services' use for charting "Scientific .. plotting of online data"  at The Virtual Observatory Spectrum Services reflects that approach. The SDSS chart authors choose to represent data using TeeChart's standard 2D line display. Speed is also a factor when choosing how to most effectively plot data. Realtime data, at frequencies of up to tens or hundreds of data points or more per second, require the most processor economic approach to charting. Computer processing time dedicated to the plotting of data needs to be as lightweight as possible, freeing-up computer tasks "to achieve real-time data acquisition, display and analysis".
An important and stated aspect of many data visualisation applications is the ability to offer interactivity to the user; NASA's document, the Orbital Debris Engineering Model ORDEM2008(Beta version), 2009, states that "The graphs may be zoomed, panned, copied to the clipboard, and exported to various file types"  and Computer and Computing Technologies in Agriculture II, Volume 1, Daoliang, Li; Chunjiang, Zhao (2009), also using TeeChart, states "the properties at any point in the chart can be viewed moving the mouse over it". Writing about control education, Juha Lindfors states "The desired charting functionality (such as zooming and scaling) is achieved..".
Charting applications have become increasingly 'onlined', made available either to a wider public or to a territorially remote userbase via networked applications. The World wide web (the Web) has become "by far, the most popular Internet protocol" to disseminate online applications. Most major IDEs now offer environments for web application developed aimed at browser hosted applications. Charting components, TeeChart among them, have adapted to provide models that work within a browser environment, often using static images and scripted layering techniques such as Ajax (programming) to offer a level of interactivity, improve response times and hide apparent delay from the user. Options to enrich client, browser-side processing flexibility are exploited by TeeChart libraries via modules that offer 'micro-environments' within the browser, such as the long established ActiveX technology, Adobe Flash, Microsoft Silverlight or Java Applets. Serverside environments offer too, a means to interact with browser based script to dynamically respond to charting requests. Joomla and CodeIgniter are host environments for TeeChart PHP and an example of an Embarcadero IntraWeb VCL designed application using TeeChart, is documented here.
The Code Project includes a demo that uses TeeChart.Lite, called 'Self-Organizing Feature Maps (Kohonen maps)' written by Bashir Magomedovl  and SourceForge includes a Database Stress and Monitor that also uses TeeChart.Lite. The Lazarus IDE for Free Pascal bundles TAChart, a similar component, for which extensive documentation is available online.
Books and information sources that include substantial sections about working with the Delphi version of TeeChart include "Mastering Delphi 6" by Marco Cantù, "C++ Builder 5 developer's guide", a video Delphi Tutorial on charting JPEG compression and support forums and reference pages at TeeChart Support Forums. Non-English language document sources include, in Czech "Myslíme v jazyku Delphi 7: knihovna zkušeného programátora" by Marco Cantù, and Chinese, Delphi 6, Delphi, and Delphi 5.
- Steema Software SL. "Steema Software Company Page". Retrieved May 2010.
- Bob Swart. "Porting Delphi 1.x code to 32-bits". Dr Bob's Delphi Programming Clinic. Retrieved May 2010.
- Embarcadero Technologies (2011), Embarcadero RAD Studio XE5 Feature Matrix, retrieved September 2013
- Steema Software SL. "Free Charting Components". Retrieved June 2010.
- Steema Software SL. "TeeChart Gallery". Retrieved May 2010.
- Steema Software SL. "TeeChart VCL / FMX specifications". Retrieved June 2010.
- Steema Software SL. "Key dates and build history". Retrieved Dec 2012.
- Embarcadero Technologies. "Delphi Version History". Retrieved June 2010.
- Biggs, Maggie (1998), "Borland Rounds out C++ Builder", InfoWorld 20 (8): 108, ISSN 0199-6649
- Tufte, Edward Rolf (2001), The visual display of quantitative information, Graphics Press, ISBN 978-0-9613921-4-7
- Budavári, Tamás (2004), "Coding against the Universe", Workshop on Service Composition for Data Exploration in the Virtual Observatory (Royal Observatory Edinburgh): 10, retrieved June 2010
- The Virtual Observatory Spectrum Services
- Zheng, Xiaofeng; Zeng, Qiyong; Wu, Kai; Yu, Zhonghua; Li, Xiaotong (2010), IEEE Computer Society, ed., Cutting Temperature and Force Data Acquisition and Measuring System Design in High Speed Machining, Changsha, China, pp. 882–885, ISBN 978-0-7695-3962-1
- , Stansbery, Eugene G.; Krisko, Paula H. (August 25, 2009), "NASA Orbital Debris Engineering Model ORDEM2008(Beta version)", Nasa Technical Reports Server (Texas: NASA Orbital Debris Program Office): 7, retrieved June 2010
- Daoliang, Li; Chunjiang, Zhao (2009), Computer and Computing Technologies in Agriculture II, Volume 1, New York: Springer Science+Business Media, p. 82, ISBN 978-1-4419-0208-5
- Lindfors, Juha (2003), Advances in control education 2003, Oxford: Elsevier, p. 172, ISBN 978-0-08-043559-6
- "History". World Wide Web. Retrieved May 2010.
- Reddy, S.M.; Mazumder, R.; Evans, D.A.D; Collins, A.S. (2009), Palaeoproterozoic Supercontinents and Global Evolution, London: The Geological Society, p. 31, ISBN 978-1-86239-283-0
- Magomedovl, Bashir (November 7, 2006). "Self-Organizing Feature Maps (Kohonen maps)". The Code Project. Retrieved May 2010.
- mehyaa (October 30, 2009). "Database Stress and Monitor". SourceForge.net. Retrieved May 2010.
- "Free Pascal wiki: TAChart documentation". Retrieved 19 September 2013.
- Cantù, Marco (2001), "Chapter 13: Delphi's Database Architecture", Mastering Delphi 6 - Mastering Series, California: Sybex, p. 550, ISBN 978-0-7821-2874-1
- Hollingworth, Jarrod (2000), C++ Builder 5 developer's guide, USA: Sams Publishing, p. 932, ISBN 978-0-672-31972-3
- Christie, Alister (July 30, 2008). "Delphi Programming Tutorial #38 - Charting Jpeg Compression". CodeGearGuru.com. Retrieved May 2010.
- TeeChart Support Forums
- Cantù, Marco (2003), Myslíme v jazyku Delphi 7: knihovna zkušeného programátora (in Czech), Praga: Grada Publishing, p. 17, ISBN 978-80-247-0694-8
- 刘艺 (2002), "Chapter 17", in DynoMedia, Delphi 6 企业级解决方案及应用剖析 (in Chinese), ISBN 978-7-111-10435-3
- 杨宗志 (2001), "Chapter 10", Delphi 数据库程序设计 (in Chinese), Beijing: Tsinghua University Press, p. 201, ISBN 978-7-900637-44-4
- DynoMedia, ed. (2000), "Chapter 9", Delphi 5 数据库开发技术 (in Chinese), p. 245, ISBN 978-7-111-07820-3