<s>
BlueJ	B-Language
is	O
an	O
integrated	B-Application
development	I-Application
environment	I-Application
(	O
IDE	O
)	O
for	O
the	O
Java	B-Language
programming	I-Language
language	I-Language
,	O
developed	O
mainly	O
for	O
educational	O
purposes	O
,	O
but	O
also	O
suitable	O
for	O
small-scale	O
software	O
development	O
.	O
</s>
<s>
It	O
runs	O
with	O
the	O
help	O
of	O
Java	B-Language
Development	O
Kit	O
(	O
JDK	O
)	O
.	O
</s>
<s>
BlueJ	B-Language
was	O
developed	O
to	O
support	O
the	O
learning	O
and	O
teaching	O
of	O
object-oriented	B-Language
programming	I-Language
,	O
and	O
its	O
design	O
differs	O
from	O
other	O
development	O
environments	O
as	O
a	O
result	O
.	O
</s>
<s>
The	O
main	O
screen	O
graphically	O
shows	O
the	O
class	O
structure	O
of	O
an	O
application	O
under	O
development	O
(	O
in	O
a	O
UML-like	O
diagram	O
)	O
,	O
and	O
objects	O
can	O
be	O
interactively	O
created	O
and	O
tested	O
.	O
</s>
<s>
Object-oriented	B-Language
concepts	O
(	O
classes	O
,	O
objects	O
,	O
communication	O
through	O
method	B-Language
calls	I-Language
)	O
are	O
represented	O
visually	O
and	O
in	O
its	O
interaction	O
design	O
in	O
the	O
interface	O
.	O
</s>
<s>
The	O
development	O
of	O
BlueJ	B-Language
was	O
started	O
in	O
1999	O
by	O
Michael	O
Kölling	O
and	O
John	O
Rosenberg	O
at	O
Monash	O
University	O
,	O
as	O
a	O
successor	O
to	O
the	O
Blue	O
system	O
.	O
</s>
<s>
BlueJ	B-Language
is	O
an	O
IDE	O
(	O
Integrated	B-Application
Development	I-Application
Environment	I-Application
)	O
.	O
</s>
<s>
Blue	O
was	O
an	O
integrated	O
system	O
with	O
its	O
own	O
programming	O
language	O
and	O
environment	O
,	O
and	O
was	O
a	O
relative	O
of	O
the	O
Eiffel	B-Language
language	O
.	O
</s>
<s>
BlueJ	B-Language
implements	O
the	O
Blue	O
environment	O
design	O
for	O
the	O
Java	B-Language
programming	I-Language
language	I-Language
.	O
</s>
<s>
In	O
March	O
2009	O
,	O
the	O
BlueJ	B-Language
project	O
became	O
free	B-Application
and	I-Application
open	I-Application
source	I-Application
software	I-Application
,	O
and	O
licensed	O
under	O
GPL-2.0-or-later	B-License
with	O
the	O
Classpath	O
exception	O
.	O
</s>
<s>
BlueJ	B-Language
is	O
currently	O
being	O
maintained	O
by	O
a	O
team	O
at	O
King	O
's	O
College	O
London	O
,	O
England	O
,	O
where	O
Kölling	O
works	O
.	O
</s>
<s>
BlueJ	B-Language
supports	O
programming	O
in	O
Java	B-Language
and	O
in	O
Stride	O
.	O
</s>
<s>
Java	B-Language
support	O
has	O
been	O
provided	O
in	O
BlueJ	B-Language
since	O
its	O
inception	O
,	O
while	O
Stride	O
support	O
was	O
added	O
in	O
2017	O
.	O
</s>
