I can't figure out if it's really slow, or hung.  Google's code tries to reload 
all 
modules (except encodings), so I extended it to leave Rpyc alone too and that 
seems 
to help.  At one point I had to tell it to leave bdb alone too, otherwise it 
would 
crash.

I get the same experience as Enrico, using Windows XP, with PyScripter 1.9.9.2.

I can run the Hello World example while the PyScripter run with 
dev_appserver.py.

When PyScripter is closed (in effect killing the run), the Hello World server 
is no
longer available.

The above is true with the Internal Python Engine.  I'll try it with the Remote 
Engine.

The run produces:
*** Remote Python engine is active ***
>>> 
Command Line : -d helloworld
INFO     2009-01-25 12:07:50,765 appengine_rpc.py] Server: appengine.google.com
WARNING  2009-01-25 12:07:50,780 datastore_file_stub.py] Could not read 
datastore
data from c:\docume~1\cjw\locals~1\temp\dev_appserver.datastore
WARNING  2009-01-25 12:07:50,780 datastore_file_stub.py] Could not read 
datastore
data from c:\docume~1\cjw\locals~1\temp\dev_appserver.datastore.history
WARNING  2009-01-25 12:07:50,780 dev_appserver.py] Could not initialize images 
API;
you are likely missing the Python "PIL" module. ImportError: No module named PIL
INFO     2009-01-25 12:07:50,796 dev_appserver_main.py] Running application
helloworld on port 8080: http://localhost:8080
DEBUG    2009-01-25 12:08:59,203 dev_appserver.py] Matched "/" to CGI 
dispatcher with
path helloworld.py

localhost:8080 on Firefox gives no result for about 30 seconds and then pythonw 
takes
50% of the cpu time - still no response to Firefox  (Dual core CPU)

I'll look into the PIL problem.

PyScripter must be closed to terminate the run.

Colin W.

I can verify that this is indeed a problem with PyScripter.

There is one way to work around the issue though, that is by placing a break 
point at 
the dev_appserver.py. But to get it working you need to input 
http://localhost:8080 a 
few times. And then your output will show on your web browser. You still can't 
step 
into your code to debug, as explained in here 
(http://stackoverflow.com/questions/789558/how-to-debug-google-app-engine-script
s-with-
pyscripter) and as what I have experienced.