Tiago Dionizio wrote on comp.lang.tcl:  I have ... written a [SQLite] based
[TclVFS] for personal use ... and it seems stable.  Used it to build a tclkit
based app without problems.  (minor text changes and hyperlinks added by [DRH])

Here is a link to the script file:
http://mega.ist.utl.pt/~tngd/tcl/sqlite3vfs.tcl

----
TD example usage:

	# mount a sqlite3 db file, store the identifier in $fd
	set fd [vfs::sqlite3::Mount test.db test]
	# now you have a test directory available in the tcl filesystem.
	
	# you can do any normal file operation on the recently added directory (filesystem)
	file copy file.txt test/file.txt
	file copy test/file.txt file2.txt
	# etc...
	
	# because modifying operations on a sqlite3 database can take some time
	# i included a special function to help with writing operations, using a single
	# transaction so it doesn't take too much time to write hundreds of files:
	vfs::sqlite3::Runlock $fd {
	    foreach f [glob *.html] {
		file copy $f test
	    }
	} # can specify lock type. ex: IMMEDIATE or DEFERRED
	
	# unmount the filesystem. (test is the local directory)
	vfs::sqlite3::Unmount $fd test