View source for BlueJ

{{Short description|IDE for Java Programming Language}}
{{Infobox software
| name = BlueJ
| logo = BlueJ Logo.svg
| logo size = 96px
| screenshot = 20210807 13 06 03-BlueJ FIX.png
| screenshot size = 250px
| caption = Screenshot of BlueJ
| author = [[Michael Kölling]] and [[John Rosenberg (academic)|John Rosenberg]]
| developer = BlueJ Team
| latest release version = 5.5.0
| latest release date = {{Start date and age|2025|06|03}}
| operating system = [[Cross-platform]]
| platform = [[Java (Sun)|Java]]
| programming language = [[Java (programming language)|Java]]
| language = [[Multilingual]]
| genre = [[Integrated development environment]]
| license = [[GNU General Public License|GPL-2.0-or-later]] with the [[GPL linking exception#The classpath exception|Classpath exception]]
| website = {{url|https://bluej.org/}}
}}
'''BlueJ''' is an [[integrated development environment]] (IDE) for the [[Java (programming language)|Java programming language]], developed mainly for educational purposes, but also suitable for small-scale [[software development]]. It runs with the help of [[Java Development Kit|Java Development Kit (JDK)]]. 

BlueJ was developed to support the learning and teaching of [[object-oriented programming]], and its design differs from other development environments as a result.<ref>{{cite book |first=M. |last=Kölling |chapter=Using BlueJ to Introduce Programming |chapter-url=http://www.cs.kent.ac.uk/pubs/2008/2697/content.pdf |editor-first=J. |editor-last=Bennedsen |editor2-first=M.E |editor2-last=Caspersen |editor3-first=M. |editor3-last=Kölling |title=Reflections on the Teaching of Programming |publisher=Springer |location= |year=2008 |isbn=978-3-540-77933-9 |pages=182–196 |series=Lecture Notes in Computer Science |volume=4821}}</ref> The main screen graphically shows the class structure of an application under development (in a [[Unified Modeling Language|UML]]-like diagram), and objects can be interactively created and tested. This interaction facility, combined with a clean, simple user interface, allows easy experimentation with objects under development. Object-oriented concepts ([[Class (computer science)|classes]], [[Object (computer science)|objects]], communication through [[Method (computer science)|method calls]]) are represented visually and in its interaction design in the interface.

== History ==

The development of BlueJ was started in 1999 by [[Michael Kölling]] and John Rosenberg at [[Monash University]], as a successor to the [[Blue programming language|Blue]]<ref name="Ref_">{{cite book |last=Kölling |first=M. |last2=Rosenberg |first2=J. |chapter=An Object-Oriented Program Development Environment for the First Programming Course |chapter-url=https://kar.kent.ac.uk/21392/1/ObjectKolling.pdf |title=Proceedings of the 27th SIGCSE Technical Symposiumon Computer Science Education |publisher=ACM |year=1996 |isbn=0-89791-757-X |pages=83–87 |doi=10.1145/236462.236514}}</ref> system. Blue was an integrated system with its own programming language and environment, and was a relative of the [[Eiffel (programming language)|Eiffel]] language. BlueJ implements the Blue environment design for the Java programming language.

In March 2009, the BlueJ project became [[free and open source software]], and licensed under [[GNU General Public License|GPL-2.0-or-later]] with the [[GPL linking exception#The classpath exception|Classpath exception]].

BlueJ is currently being maintained by a team at [[King's College London]], England, where Kölling works.

=== Supported language ===

BlueJ supports programming in [[Java (programming language)|Java]] and in Stride.<ref>[http://stride-lang.net Stride]</ref> Java support has been provided in BlueJ since its inception, while Stride support was added in 2017.

== See also ==
{{Portal|Free and open-source software|Computer programming}}
* [[Greenfoot]]
* [[DrJava]]
* [[Educational programming language]]

== References ==
{{reflist}}

== Bibliography ==
{{refbegin}}
*{{Cite book
| first1    = David J.
| last1     = Barnes
| first2    = Michael
| last2     = Kölling
| date      = May 12, 2011
| title     = Objects First with Java: A Practical Introduction Using BlueJ
| edition   = 5th
| publisher = [[Prentice Hall]]
| pages     = 560
| isbn      = 978-0-13-249266-9
| url       = http://www.pearsonhighered.com/pearsonhigheredus/educator/product/products_detail.page?isbn=9780132492669
}}
*{{Cite journal
| first1    = Michael
| last1     = Kölling
| first2    = Bruce
| last2     = Quig
| first3    = Andrew
| last3     = Patterson
| first4    = John
| last4     = Rosenberg
| date      = Aug 9, 2010
| title     = The BlueJ System and its Pedagogy
| journal  = Computer Science Education
| volume     = 13
| issue     = 4
| pages     = 249–268
| doi     = 10.1076/csed.13.4.249.17496
| citeseerx     = 10.1.1.22.3975
| s2cid = 2805887
}}

{{refend}}

== External links ==

* {{Official website|http://www.bluej.org}}
* [http://www.bluej.org/objects-first/ BlueJ textbook]

{{Integrated development environments}}
{{Sun Microsystems}}

{{DEFAULTSORT:Bluej}}
[[Category:Integrated development environments]]
[[Category:Free integrated development environments]]
[[Category:Cross-platform free software]]
[[Category:Free software programmed in Java (programming language)]]
[[Category:Java development tools]]
[[Category:Java platform]]
[[Category:Linux programming tools]]
[[Category:Software development kits]]
[[Category:MacOS programming tools]]
[[Category:Programming tools for Windows]]
[[Category:Linux software]]
[[Category:Educational programming languages]]
[[Category:Pedagogic integrated development environments]]
[[Category:1999 software]]