IEEE Robotics & Automation Magazine - September 2013 - 89

Player in Education
at the University of Auckland
By Bruce MacDonald
We have used Player in our robotics laboratory since 2004.
We found from the start that Player was quite accessible to
graduate students, reducing the time to come up to speed in
programming any particular robot, and made it much easier
for a student to take over a project from someone who had
ﬁnished his/her study. Once the graduate students were
comfortable with Player, we introduced it in the Robotics
and Intelligent Systems course of the ﬁnal undergraduate
year. We ask these students to create a simple client for
a following, foraging, manipulation, or navigation task.
Students initially use Stage to test their clients. We use seven
Pioneers, each with a simple arm, so that students can have
some practical experience programming real robots. As a
result, they are prepared to take up graduate study without
any delay in learning how to program our robots. About
70-80 students take the course each year, with backgrounds
in several different engineering disciplines. The organization
of Player has encouraged students to improve the code
base and to contribute ideas back. One group in their ﬁnal
year project improved the 2.5-D version of Stage, which
illustrates how accessible the project is. Player has enabled
a strong educational program in robotics, with an excellent
progression to research projects.

the programmer into a particular controller structure. Player
allowed the programmer to choose their own structure. Player
also supported a variety of languages, while its contemporaries
were typically limited to one, often custom-designed, language. Over the years, Player has supported C, C++, Java, Tcl,
Python, Common Lisp, Matlab, and more.
It is recognized among open-source projects that a strong
community is the key to a successful project. Player's developers cultivated a community around the project. Brian Gerkey
was notable on the mailing lists for quickly answering any
questions. The project as a whole was very open, with submitted patches quickly accepted into the source, irrespective of
their origin, coding style, or even if they worked perfectly
("any code is good code"). The European summer school on
Player was arguably a major driver in Player's growth in
Europe (see also "Player's Role for European Academics").
Player's strong community, which continues to this day, has
allowed it to survive three generations of developers.
Stage was undoubtedly a major factor in Player's initial and
continuing success. By providing integrated support for a
robot simulator, Player greatly increased its applicability and
usefulness. The appearance of the 3-D Gazebo simulator in
2002 reinforced this. Stage, often assumed to be an offshoot of
Player, actually predates it, as the Arena simulator [see Figure
7(a)] and was one of the inspirations for Player's development. While the models in stage began by closely emulating
Pioneer robots, as Player's interfaces became more generic, so
too did Stage's models. They proved to be a useful test of new
interface designs, as implementing the complete interface in a
Stage model revealed ambiguities and contradictions [6]. This
helped improve Player for its users. Stage has changed much

Player's Role for European Academics
By Radu Bogdan Rusu
We started using Player around 2004 for student projects,
performing experiments in Stage with multiagent system
architectures. Its dedicated team of developers and their
insatiable need to help newcomers made it very appealing
for a lot of users to transition to becoming contributors, as
they found the Player project compatible with their own
needs. There was simply nothing of that kind in robotics
at that point: a friendly talented team of international
researchers and engineers working together on making
robots useful, without any boundaries on how the project's
capabilities could be extended or what the project could be
useful for.
Some of the ﬁrst contributions from Europe came in
the form of Player client libraries, with the Java client being
one of the stronger contributions. Later on, advances in
heterogeneous sensor networks for robotics applications
and better 3-D sensing devices led to important
contributions to Player in the form of new interfaces and
drivers [23].
The Player Summer School took place in Munich,
Germany, at the Technische Universitaet Muenchen (TUM),
in the autumn of 2007. Being co-organized by TUM and
SRI International, and with sponsorship from the European
Robotics Network (EURON), the event was a major success.
It brought together more than 50 students from all around
the world for a seven-day marathon through Player for
Cognitive Robotics Research. We had the pleasure of being
able to assemble the entire Player core development
team in one place, together with a list of top worldwide
scientists and researchers, and cover topics from navigation
to higher level reasoning, with a stop at Munich's famous
Hofbrauhaus brewery in the middle.
It was after the 2007 summer school that Player began
getting an amazing response from the European community,
with many contributions and fresh ideas ﬂowing in.

over the years. It is now a very powerful 2.5-D simulator.
Figure 7(b) illustrates Stage as it is now.
The wide range of hardware support in Player is
another factor in its success. When looking for software
for a robot, one that already works is more likely to be
chosen. When users then added additional drivers for
their extra hardware, Player's support grew more, further
attracting new users.
Not every aspect of Player was a success. New technical features were sometimes ignored by the user community. For
example, both the driver properties API and driver capabilities
API were largely ignored. This may, in part, have been due to
insufﬁcient publicity about the features. Player also attempted
to remove the choice between "push" and "pull" data modes,
only to add it back at the last minute prior to Player 2's release,
upon ﬁnding that it introduced a serious limitation.
The Future of Player
Player has been through two generations of main developers and a major design overhaul since it began, and development of major new features is slowing. The Player 3
release did not feature any major new architectural
september 2013

IEEE ROBOTICS & AUTOMATION MAGAZINE

Table of Contents for the Digital Edition of IEEE Robotics & Automation Magazine - September 2013