godoc.org table of basename duplicates (grouped by number of duplicates)

5-or-more-dups.txt

57	config
48	util
37	client
32	log
28	web
27	server
26	cache
25	model
23	core
23	redis
22	utils
22	parser
18	errors
18	app
17	types
17	test
17	src
17	proto
16	fs
16	token
16	common
16	db
15	http
15	session
15	api
15	auth
15	controllers
14	matrix
13	atom
13	sdl
13	scanner
13	v1
13	oauth
12	testing
12	reddit
12	conf
12	graph
12	schema
12	context
12	user
12	stack
12	mock
12	rpc
11	trie
11	models
11	s3
11	forms
11	html
11	store
11	tests
11	twitter
10	queue
10	term
10	color
10	lib
10	mysql
10	ui
10	bson
 9	memcache
 9	uuid
 9	irc
 9	sessions
 9	data
 9	datastore
 9	bencode
 9	trunk
 9	ast
 9	base
 9	proxy
 9	hello
 9	gl
 9	resize
 9	view
 9	stats
 9	state
 9	logger
 8	cmd
 8	net
 8	service
 8	bot
 8	parse
 8	golog
 8	gfx
 8	set
 8	math
 8	lexer
 8	aws
 8	json
 8	ini
 7	env
 7	filter
 7	version
 7	protocol
 7	text
 7	raster
 7	router
 7	i18n
 7	pat
 7	file
 7	cpu
 7	nbt
 7	handlers
 7	game
 7	tools
 7	newmath
 7	terminal
 7	packet
 7	plugin
 7	assert
 7	v2
 7	glib
 7	stat
 6	vector
 6	worker
 6	templates
 6	fuse
 6	btree
 6	block
 6	yaml
 6	pbkdf2
 6	xml
 6	engine
 6	rest
 6	image
 6	storage
 6	event
 6	search
 6	xmpp
 6	ldap
 6	pcap
 6	pq
 6	imap
 6	leveldb
 6	input
 6	google
 6	facebook
 6	mgo
 6	shortie
 6	readline
 5	statsd
 5	zipfs
 5	dns
 5	io
 5	xgb
 5	spdy
 5	render
 5	httputil
 5	doc
 5	mux
 5	sparse
 5	transform
 5	log4go
 5	template
 5	inotify
 5	memory
 5	descriptor
 5	doozer
 5	gtk
 5	tiff
 5	mail
 5	canvas
 5	blas
 5	validate
 5	perlin
 5	generator
 5	exif
 5	curses
 5	registry
 5	hash
 5	pretty
 5	goconf
 5	backend
 5	goconfig
 5	glfw
 5	index
 5	lex
 5	ec2
 5	geometry
 5	seq
 5	rss
 5	key
 5	admin
 5	table
 5	treap
 5	controller
 5	helper
 5	netchan

gistfile1.txt

dups    n
   1    3585    (49.36%)
   2    517     (14.24%)
   3    183     (7.56%)
   4    74      (4.08%)
   5    48      (3.30%)
   6    27      (2.23%)
   7    23      (2.22%)
   9    18      (2.23%)
   8    13      (1.43%)
  12    10      (1.65%)
  11    8       (1.21%)
  10    7       (0.96%)
  13    5       (0.89%)
  15    5       (1.03%)
  16    4       (0.88%)
  17    4       (0.94%)
  18    2       (0.50%)
  22    2       (0.61%)
  23    2       (0.63%)
  14    1       (0.19%)
  25    1       (0.34%)
  26    1       (0.36%)
  27    1       (0.37%)
  28    1       (0.39%)
  32    1       (0.44%)
  37    1       (0.51%)
  48    1       (0.66%)
  57    1       (0.78%)

1 dup means no duplicates (thus 49% of packages have unique basenames). All these stats are based solely on the last path component, which in many cases does lose a bit of information.