Scratch

Hi! I'm Julián, Minibloq's author. First, Nice post! Second: thanks for mention Minibloq. I think I can help with this thread, since I love graphical programming. Here are my comments/ideas:

1. I would like to say that perhaps there are also other important questions about the environments. For example, these may be important for important for some users:
f) Is the software free?
g) Is it open source or a propiertary solution (may be free but not OS.).
h) Does it run online or offline? (the first is more portable, but not all countries and schools has reliable internet access).
i) In which operating systems does it run?
j) Which boards does it support?
k) Can it be extended? How, recompiling or just editing text files?

2. Answers to some of your questions (and mine) about Minibloq:
a) As I'm the author, I will not answer to this.
b) It's general. The limitations are temporal, as for other environments. We are working on more datatypes, user blocks, etc..
c) It's active.
d) It's not much influenced by Scratch. It runs stand alone, and can even run from a pendrive (self contained, includes the compilers, drivers, terminal, etc.).
e) Still needs to mature, but has some really interesting features, like automatic variable management, real time error checking, and a nearly unique feature: real time code generation. Another thing important about it is that it's contextual: it only shows to the user the blocks he can fit in that specific place, so the environment does not show "all the block categories" at the same time.
f) Free.
g) Open source.
h) Runs offline, written in C++.
i) Windows (XP, Vista, 7). The native Linux version is running internally, but still has some bugs. Does not run in Mac.
j) Boards: Nearly all Arduino family (but not Lilypads yet), plus 32 bit ARM based Maple (preliminary support), ATTiny25, 45, 85 and DuinoBots.
l) Blocks can be added by advanced users/developers editing XML files (http://blog.minibloq.org/p/development.html). To add hardware in the current version, it's still necessary to recompile. Next version will most probably feature a full backend to add hardware with XML.

3. There are other important environments to program Arduino compatible and other hardware boards. One wich is Scratch influenced is Ardublock (ardublock.com). Regarding your questions (and adding mine questions also), this environment is:
a) In my own experience, it works (may have some minor bugs, but it's a young project)
b) It's general. The limitations seems to be temporal, as for other environments.
c) It's active.
d) It's heavily influenced by Scratch, and it's a plugin for the Arduino IDE.
e) Still needs to mature, but has some really interesting features.
f) Free.
g) Open source.
h) Runs offline, written in Java.
i) Windows (XP, Vista, 7), Linux, Mac OS X.
j) Boards: Supports nearly all that can be programmed from the standard Arduio IDE
k) As it relies on the Arduino IDE, the plugins and boards that can be added to the IDE in general may work with Ardublock.
l) I'm not sure.

Another but not fully graphical (but with a very different and interesting approach) is Physical E-toys (http://tecnodacta.com.ar/gira/projects/physical-etoys/), based on Squeak. I don't have much experience with it, but in it's last version has some really nice features.

I hope this can help...

Cheers!
Julián
http://minibloq.org
http://multiplo.org

I made a serial command console that allows you to test connections with arduinos.
I'll post the link.

works just like a phone line terminal!

Hi, I'm Koji, developer of Scrattino for Arduino.
It's active project and used at an university class in Japan.

I'll attend Scratch@MIT 2012. If you are interested in it, let me know on twitter @yokobond .

a) does it work? ...and with the latest Arduino, ie 'Uno'?
Scrattino works on any Arduino. Because it uses standard Firmata protocol.

b) is it full and general? or only some sensors or other limitations?
It has general api as same as Firmata. Firmata senses analog/digital inputs and control digital/PWM outputs. On the other hand, Scrattino is not a compatible with ScratchBoard(PicoBoard) strictly. Its input/output data are 1024 resolution, not 100. It has no special sensors, direct values are coming from input pins.

c) is it actively maintained/updated?
Scrattino is fully implemented. It is maintained on demand.

d) is it "an addon library"? extended Scratch clone? Sth else?
Scrattino is a data exchange server application. You should run Scrattino besides Scratch.
It is build on Squeak, so that it can run on Windows/Mac/Linux.

e) ...and what are your experiences/opinions/reflections on these?
Scratch+Arduino is a simple compatible with ScratchBoard. It could not control outputs but easer than Scrattino.

f) Is the software free?
Yes, it's free.

g) Is it open source or a propiertary solution (may be free but not OS.).
It's open source project under MIT license.

h) Does it run online or offline? (the first is more portable, but not all countries and schools has reliable internet access).
Scrattino run offline.

i) In which operating systems does it run?
Scrattino runs in Windows/Mac/Linux.

j) Which boards does it support?
Scrattino supports all Arduino which uploaded Firmata.

k) Can it be extended? How, recompiling or just editing text files?
Yes, Scrattino can be extended in Squeak Etoys scripting. It can be modified dynamically and graphically.