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The Programming Languages Beacon
v19 - September 2025

This table contains a list of major software products or utilities, with details about the programming languages used to implement them. Information on this is difficult to find, and a few small mistakes might have escaped the author's attention. Corrections, suggestions for additions or even references are welcome. The list is not supposed to be exhaustive but the most significant products are tentatively listed. The order of the products in each family obeys no specific rule, the reader should not understand it as a ranking.
The main programming language, the one with which most of new developments are done, is highlighted, while the ones used in older times and still present, or used only for a minority of the developments are indicated too. The pieces of software listed are usually very large, and the list of programming languages cannot be exhaustive. Miscellaneous languages are not mentioned. Sometimes, there are different products under the same line (eg "Games"), or different implementations of a single line (eg JVM implementations). In this case, the overwhelming trend is indicated. Miscellaneous counter examples are ignored.
Some readers believe that most of the applications presented are based on old code, and that the technologies in use reflect the trends of the time. As it is an erroneous belief, some introduction dates are mentioned, like here, or here to show that what is "new" or "old" technology does not necessarily correspond to intuition.

The difference between C and C++ is a bit artificial, as it is always possible to argue that most of C code is C++ code, or conversely (as more than a few people use C++ more or less like C). The approximation made in this document tries to correspond to intuition.

Image indicates the major programming language for current evolutions.
Image refers to a technology which is present, but is either stable or decreasing.
Image means that the product has died, and when it died, it used that technology
Image is meant to show an evolution towards the column it points to.

When the arrow is alone, it means that the amount of code corresponding to the technology in this column is either now null or negligible, having evolved in the direction of the arrow.

The readers who might find the content of this page paradoxical will find a tentative explanation of the phenomenons at stake here. Read the section entitled "Time will come when computers will be fast enough".

11,425 visits to this page on the 12th of April 2012 over 24h, record beaten!

Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Operating systems
Microsoft Windows
Image
ImageImage
Image
 Some attempts were made to put some C# in Windows Mobile (e.g. the soft keyboard). The result was judged too slow to be incorporated in the final product and was reverted to C++.
The windows kernel is written in C (and compiled as C).
The amount of assembler is limited to a few thousand lines.
Linux
    
Image
          
   
Image
Image
     Objective-C The first version of user interface of the MacOS was inspired by the Xerox Alto user interface which introduced the WIMP concept. The user interface was implemented in SmallTalk, and to run it, the hardware was far too expensive for mass market. Early versions of MacOS used Assembler and Pascal.
Sun Solaris
    
Image
          
HP-UX    
Image
          
Google Chrome OS
2009
  
Image
Image
       Google Chrome is based on Linux and Chrome.
OSv
2013
Image
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Operating systems for mobiles
2007
Image
Image
 Objective-C The iPhone, iPod Touch and iPad use a modified version of Mac OS.
Google Android
2008
Image
Image
Image
 Android is based on Linux, which is coded in C. The user interface is Java. Apps (not covered here) are mostly Java.
Amazon Kindle OS
2007
  
Image
         The Kindle runs Linux.
Symbian OS
  
Image
  

Image
(2013)

      Symbian was still the leading operating system for phones in 2010. Its market share dropped to 4.4% in Q2 2012. It has been declared dead on January 24, 2013.
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Graphical Layers
Microsoft Windows UI      
Image
        
Apple MacOS UI (Aqua)      
Image
        
Gnome    
Image
Image
        
KDE      
Image
        
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Desktop Search
Google Desktop Search      
Image
        
Microsoft Windows Desktop Search      
Image
        
Beagle          

Image
(2009)

   
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Office products
ImageImage
ImageImage
Image
 Traditionally, MS Office was developed using assembler, then development moved to C, later, when C++ arose, everything new was done using C++. Currently there is no plan to change. A small attempt was made to develop a miscellaneous single panel in C#, a few years back. It is not known if it has been kept. At CppCon 2022 a Microsoft employee made a presentation stating that Microsoft Office contains 350 million lines of C++.
Image
Image
 Apache Open Office, acquired in 1999 by Sun Microsystems from Star Division. No attempt has been made by Sun to convert the code into Java. Java is however used for some miscellaneous modules.
Image
Image
 Python This is a fork of OpenOffice. The code is still mainly C++. Some Python added.
Image
 JavaScript inside the browser.
Image

Image

(August 1997)

Corel Office, initially developed in Assembler and C, moved to Corel Office for Java, fully developed in Java for portability in 1996, and abandoned in August 1997 because it was too slow. The code was later redeveloped using C and C++.
Adobe Systems Acrobat Reader/Distiller
Image
Evernote
Image

Image

(October 2010)

Evernote v3.5 was coded in C#. The technology had to be changed to gain speed. The current programming language from v4.0 is C++.
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
RDBMS
Oracle database
Image
Image
Image
Image
 Only Assembler, C and C++ in the core.
MySQL
Image
Image
MariaDB
Image
Image
 Perl MariaDB is a fork of MySQL. More than half of the code is C++. The remainder is made of C and Perl.
IBM DB2
Image
Image
Image
Microsoft SQL Server
ImageImage
ImageImage
Image
IBM Informix
Image
Image
Image
SAP DB/MaxDB
Image
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
NoSQL and document databases, big data
Google File System
Image
Google BigTable
Image
Image
 Python, Go, Ruby At Google, all infrastructure is done using C++, and C++ alone. Peripheral functions can be developed using other languages.
Apache Hadoop
Image
 Hadoop is inspired from Google File System.
Apache Cassandra
Image
ScyllaDB
2015
Image
 ScyllaDB is a C++ rewrite of the Java-based Apache Cassandra. It claims a 10-fold improvement in performance over Cassandra. This would be at least in part due to the usage of a C++ framework: Seastar.
MongoDB
2009
Image
CouchDB
 Erlang
Couchbase Server
2015
Image
 Couchbase source base, initially CouchDB, was first Erlang-based, like CouchDB. Then some Go was added. In 2012, 2+ man months chasing a very low level race bug in Erlang's virtual machine, Erlang was not considered trustable, and C was gradually introduced. In 2013, Damien Katz wrote about his discovery of C's merits. In spite of Katz' criticism of C++, after his departure from Couchbase, the code was actively converted to C++.
LevelDB
2011
Image
 Done by Google.
RocksDB
2016
Image
 Fork of LevelDB done by Facebook.
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Data science, machine learning
TensorFlow
Image
 Python TensorFlow GitHub gives the breakdown of languages. As of 2022, TensorFlow is made of 62.8% C++, 21.9% Python and miscellaneous other languages.
Theano
Python Theano GitHub gives the breakdown of languages. As of 2022, Theano is made of 93.9% Python.
Requests
Python Requests GitHub gives the breakdown of languages. As of 2022, Requests is made of 99.8% Python.
Apache Spark
Scala
scikit-learn
Python, Cython
OpenCV
Image
 OpenCV GitHub gives the breakdown of languages. As of 2022, OpenCV is made of 86.1% C++, 3.7% C and miscellaneous other languages.
NetworkX
Python
mlpack
Image
 Mlpack GitHub gives the breakdown of languages. As of 2022, mlpack is made of 95% C++ and miscellaneous other languages.
PyTorch
Image
 Python PyTorch GitHub gives the breakdown of languages. As of 2022, PyTorch is made of 51% C++, 38.6% Python and miscellaneous other languages.
Chainer
Python
Dlib
Image
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Web browsers
Microsoft Edge (ex. Internet Explorer)
2014
Image
Mozilla Firefox
      
Image
        
Netscape Navigator
    
ImageImage
see Mozilla
ImageImage
     The code of Netscape browser was written in C, and Netscape engineers, all bought to Java (see M. Cusumano book and article) redeveloped the browser using Java. It was too slow and abandoned. Mozilla, the next version, was later developed using C++.
Safari
7-Jan-03
Image
 Browser for Apple Mac OS, its foundation is WebKit, a C++ framework.
Google Chrome
2-Sept-08
Image
 Chrome has been introduced as the combination of 26 different libraries. The base code comes from WebKit (C++) which powers Safari as well. One of its key propositions is the ultra fast V8 JavaScript engine, written essentially in C++.
Sun HotJava

Image
(1999)

 HotJava never took off, it was far too slow compared to other browsers. It became a showcase for the Java applet technology and the product is now frozen since 1999.
Opera
Image
Opera Mini
Image
Image
 Pike Opera Mini (2007) has a very funny architecture, and is indeed using C++, Java and Pike. The browser is split in two parts, an ultra thin (less than 100Kb) "viewer" client part and a server side responsible of rendering. The first uses Java and receives the page under the OBML format, the latter reuses classical Opera (C++) rendering engine plus Opera's Small Screen Rendering, on the server. A significant part of the server uses Pike. This original architecture allows Opera to penetrate various J2ME-enabled portable devices, such as phones, while preserving excellent response time. This comes obviously with a few sacrifices, for instance on JavaScript execution.
Mosaic
Image
 Mosaic was the first widely spread browser, it morphed into Netscape.
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Mail clients
Microsoft Outlook
Image
IBM Lotus Notes
Image
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Development environments
Microsoft Visual Studio
Image
Image
 Visual Studio 2010 was still mostly native code, but for the UI presentation it adopted the managed WPF framework. This holds true for later versions. plug-ins are also using more and more C#.
Eclipse
Image
(see notes)
     To build Eclipse, a specific graphical toolkit was developed, SWT to replace Java classical AWT or Swing (considered too slow). SWT is a thin Java layer on top of native C/C++ code. SWT is now part of Eclipse RCP.
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Version control
git
Image
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Virtual machines
Microsoft .Net CLR
Image
Java Virtual Machine (JVM)
Image
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
ERP, CRM
SAP ERP    
Image
Image
    
Image
ABAP
 SAP ERP is programmed in ABAP, which generates C code. The SAP kernel is itself coded using C and C++.
Oracle Peoplesoft      
ImageImage
Image
  
Image
PeopleCode
Peoplesoft relied on BEA Tuxedo and C++ code, now moving to Oracle WebLogic and Java, keeping the PeopleCode language. The C++ code is apparently not reengineered.
Oracle E-Business Suite        
Image
      
Salesforce        
Image
      
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Business Intelligence
Business Objects      
Image
        
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Graphics Editors
Adobe Photoshop      
Image
        
The GIMP    
Image
          
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Search Engines
Google  
Image
  
Image
        
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Web Sites
eBay      
(2002) Image
Image
     Information on eBay architecture and the move from C++ to Java can be found here.  
PayPal      
Image
        
Amazon      
Image
Image 
     Amazon initially using C++ extensively is now using an increasing amount of Java.
facebook
26-Sep-2006
    
Image
    
Image
PHP
 This line is only about facebook, not its plugins. Plugins can be developed in many different technologies, thanks to facebook's ORB/application server, Thrift. Thrift contains a compiler coded in C++. facebook people write about Thrift: "The multi-language code generation is well suited for search because it allows for application development in an efficient server side language (C++) and allows the Facebook PHP-based web application to make calls to the search service using Thrift PHP libraries." Aside the use of C++, facebook has adopted a LAMP architecture.
In 2009 and 2010, facebook developers have made a shift towards C++ with HipHop, a PHP to C++ translator which allows to reduce by 50% the hardware needed to operate the site.
YouTube      
Image
       Python was removed not long after the acquisition by Google in 2006.
LinkedIn        
Image 
      
DropBox             Python, Go, Rust For details, have a look here.
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Games
Image
Image
Image
 A lot of games on smart phones are developed using Java. This entry refers to "full service" disk based games.
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Compilers/interpreters
Microsoft Visual C++
Image
Microsoft Visual Basic
Image
Microsoft Visual C#
Image
 It is worth noting that Microsoft is running a project called Roslyn which contains a C# compiler written in C#.
gcc (GNU Compiler Collection)
Image
Clang/LLVM compiler suite
Image
javac (Sun Java compiler)
Image
Perl
Image
PHP
Image
 It must be noted that PHP is a script running a lot of imported libraries, themselves either programmed in C or C++.
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
3D engines
Microsoft DirectX
Image
OpenGL
Image
Unity
Image

Image
(scripting)
OGRE 3D
Image
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Web Servers
Apache    
Image
Image
        
Microsoft IIS      
Image
        
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Mail Servers
Microsoft Exchange Server    
ImageImage
Image
        
Postfix    
Image
          
hMailServer      
Image
  
Image
    
Apache James        
Image
     Apaches James has not evolved as a stable release since 2009.
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Web 2.0
MediaWiki PHP Powers Wikipedia
TWiki Perl
Google Blogger Python The software has been re-engineered several times, for instance in 2002 and 2006.
Google Wave 2009

Image
(August 2010)

Google Wave user interface used Google Web Toolkit. which allowed to program the UI using Java and generate JavaScript code. The server used Java too.
Flickr PHP
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Digital audio editors
   
Image
Image
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
CD/DVD Authoring
Nero Burning ROM      
Image
        
K3B      
Image
        
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Multimedia Players
Image
Image
 Objective-C, Lua
Nullsoft Winamp      
Image
        
Microsoft Windows Media Player      
Image
        
Apple iPod software      
Image
        
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Peer to Peer
eMule      
Image
        
�torrent      
Image
        
Vuze (previously Azureus)        
Image
     Vuze is built on top of SWT, see notes corresponding to Eclipse.
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
GPS Systems
TomTom      
Image
        
Hertz NeverLost      
Image
        
Garmin      
Image
        
Motorola VIAMOTO
2003
      

Image
(June 2007)

    Motorola VIAMOTO was a smart phone "connected" GPS implementation, with a Java client-side. It was re-branded by a number of car rental companies. For instance, Avis Assist was another name for the Motorola VIAMOTO product. Avis have withdrawn this product and are now offering Garmin in the USA and TomTom in Europe. Motorola withdrew the product in June 2007. Alamo/National who had re-branded the system "Navigation Station" will also discontinue the service.
Family/Product
Date
ASM
C
C++
Java
C#
Others
Notes
Universal remotes
Logitech Harmony 1000/1100 2009

Image
(2009)

Image
Flash
 The UI of the Harmony 1100 is now Flash based vs the Java UI found in the Harmony 1000.

This page is maintained by Vincent Lextrait (e-mail vincent@lextrait.com)