Is there any command that removes orphaned packages in Solaris ? Or a program similar to gtkorphan from Debian ?
What exactly do you mean by an "orphaned package" ?
Well, I was thinking of a program that can remove obsolete files (pastremaining files of previous software uninstallations).
like a service that has no dependancies?
Yes. How do I do it ? 
i don't think there is a tool for something like that...
as usual, duke is right.
however, the only thing that comes to mind is svcs command.
example:
bash-3.00$ svcs -l svc:/milestone/single-user:default
fmri svc:/milestone/single-user:default
name single-user milestone
enabled true
state online
next_state none
state_time Mon May 28 01:38:48 2007
logfile /var/svc/log/milestone-single-user:default.log
restarter svc:/system/svc/restarter:default
dependency require_all/none svc:/system/identity:node (online)
dependency require_all/none svc:/system/filesystem/minimal (online)
dependency require_all/none svc:/milestone/devices (online)
dependency require_all/none svc:/system/manifest-import (online)
dependency require_any/none svc:/network/loopback (online)
dependency optional_all/none svc:/milestone/network (online)
dependency optional_all/none svc:/system/metainit (online)
dependency optional_all/none svc:/system/cryptosvc (online)
dependency require_all/none svc:/system/sysevent (online)
or
bash-3.00$ svcs -d svc:/milestone/single-user:default
STATE STIME FMRI
online May_28 svc:/network/loopback:default
online May_28 svc:/milestone/network:default
online May_28 svc:/system/identity:node
online May_28 svc:/system/metainit:default
online May_28 svc:/system/filesystem/minimal:default
online May_28 svc:/system/sysevent:default
online May_28 svc:/milestone/devices:default
online May_28 svc:/system/cryptosvc:default
online May_28 svc:/system/manifest-import:default
Thank you pupp.