On Tuesday 27 May 2008 22:02:32 Irene Markelic wrote:
> Hi everybody,
> for a bigger project I need to make a design choice. I have read through
> the documentations of several software packages, mainly orocos, yarp and
> claraty, but it is very difficult to get all the information from just
> that. So I ask you, why you use orocos and not yarp or claraty? Do you have
> any recommendations based on your experience?

For starters, I don't have experience on Yarp. I did have a short look on the
class reference and the tutorial. Also, I don't like Claraty for several
reasons. The main reason is that it's not Free Software.

I'm not at all familiar with Yarp, so Yarp fans may correct me where I'm
wrong, especially, I can't give many pro's/better features about Yarp.

The Orocos Real-Time Toolkit and Yarp have the following commonalities:
* They are portable
* They use 'flow ports' for data communication (many-to-many)
* They use signals or events (although probably differently)
* Both allow network and local communication
* They target robotics

The differences are many however:
* Yarp is GPL, Orocos is LGPL (or equivalent)
* Yarp provides classes/types which are application specific, the RTT is
application independent, you can use your own data types.
* Yarp has a primitive 'component model' (the 'module'). In Orocos, components
can be configured, started, stopped, re-configured, have error states etc.
* The RTT has a run-time scripting interface and scriptable state machines,
one of the best/most used features it offers
* Orocos components can be configured using XML files, one of the best/most
used features it offers
* Orocos applications can (optionally) be built using XML files, one of the
best/most features features it offers
* The RTT is more complex, but is also more powerful (or necessary) for
complex applications
* Yarp looks (and sounds) a lot funnier and has a better website
* Orocos provides a library for kinematics, Yarp looks more vision based, but
I might be wrong here.

In my opinion, Orocos has left conventional tracks on many places while Yarp
(as its name implies) has followed in the footsteps of its ancestors. This
causes Orocos development to be of a more dynamic nature, while I'm guessing
Yarp has quite matured and finished its framework...

Peter

On Tue, 27 May 2008, Irene Markelic wrote:

> for a bigger project I need to make a design choice. I have read through
> the documentations of several software packages, mainly orocos, yarp and
> claraty, but it is very difficult to get all the information from just
> that.
> So I ask you, why you use orocos and not yarp or claraty? Do you have any
> recommendations based on your experience?
>
All three projects have had a different history, and different motivations
behind their creation. For Orocos, the focus has been on realtime, and on
_not_ wanting to include middleware in the project (there are (too) many
middleware projects out there already). Somewhat later, we added (basic)
Bayesian algorithms and (basic) kinematics to our scope. I think Orocos is
still the only one with these three focus points. Other projects have had
other priorities (which is great, in fact).

But, as a potential new user of open source robotics projects, _the_
question to ask is not which project to use, but to give _concrete_
suggestions to all the projects you are interested in about on which
domains they should begin to work together more closely, to avoid code
duplication, to increase standardization, in order to reach the only goal
that is really important in the long run: complete interoperability.

Herman

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