Clean up my RoR development environment - ruby

Question

I started RoR development a few months ago, and being new to Mac...
Time flies and now I have a lot different ruby versions, rails versions and gems versions located everywhere......And currently I installed rvm and things got even worst, all things messed!
And so I started want to clean all things and use rvm again! I want to uninstall all gems, all rails, and all ruby versions, except the system's default one (the very old one born with the mac).
Or any other better solutions or suggestions!? Please help!
there is some info that I think will be useful:
which -a ruby
/opt/local/bin/ruby
/opt/local/bin/ruby
/usr/local/bin/ruby
/usr/bin/ruby
/usr/local/bin/ruby
which -a rails
/usr/local/bin/rails
/usr/bin/rails
/usr/local/bin/rails
which -a compass # simliar for rspec and many other gems
/usr/local/bin/compass
/usr/local/bin/compass
gem list
*** LOCAL GEMS ***
abstract (1.0.0)
actionmailer (3.0.3, 3.0.1, 3.0.0, 3.0.0.rc2, 2.3.9, 2.3.5, 2.3.4)
actionpack (3.0.3, 3.0.1, 3.0.0, 3.0.0.rc2, 2.3.9, 2.3.5, 2.3.4)
activemodel (3.0.3, 3.0.1, 3.0.0, 3.0.0.rc2)
activerecord (3.0.3, 3.0.1, 3.0.0, 3.0.0.rc2, 2.3.9, 2.3.5, 2.3.4)
activeresource (3.0.3, 3.0.1, 3.0.0, 3.0.0.rc2, 2.3.9, 2.3.5, 2.3.4)
activesupport (3.0.3, 3.0.1, 3.0.0, 3.0.0.rc2, 2.3.9, 2.3.5, 2.3.4)
addressable (2.2.2)
arel (2.0.6, 1.0.1, 1.0.0.rc1)
authlogic (2.1.6, 2.1.3)
aws-s3 (0.6.2)
base32 (0.1.2)
block_helpers (0.3.3)
bluecloth (2.0.9)
bowline (0.9.4)
bowline-bundler (0.0.4)
bson (1.1.2)
builder (2.1.2)
bundler (1.0.2, 1.0.0)
compass (0.10.6)
crack (0.1.7)
devise (1.1.3)
diff-lcs (1.1.2)
differ (0.1.1)
dynamic_form (1.1.3)
engineyard (1.3.1)
engineyard-serverside-adapter (1.3.3)
erubis (2.6.6)
escape (0.0.4)
extlib (0.9.15)
facebooker (1.0.75)
faker (0.3.1)
faraday (0.5.3, 0.5.2)
fast_gettext (0.5.10, 0.4.17)
fastercsv (1.5.3)
fastthread (1.0.7)
ffi (0.6.3)
formatize (1.0.1)
formtastic (1.1.0, 1.0.1)
gemcutter (0.5.0)
gettext (2.1.0)
git (1.2.5)
gosu (0.7.25 universal-darwin)
haml (3.0.24, 3.0.23, 3.0.22, 3.0.21, 3.0.18)
haml-rails (0.3.4)
heroku (1.10.13, 1.9.13)
highline (1.5.2)
hirb (0.3.4, 0.3.3)
hpricot (0.8.2)
i18n (0.5.0, 0.4.2, 0.4.1, 0.3.7)
jeweler (1.4.0)
json (1.4.6)
json_pure (1.4.3)
linkedin (0.1.8)
locale (2.0.5)
mail (2.2.12, 2.2.11, 2.2.10, 2.2.9, 2.2.7, 2.2.6.1)
memcache-client (1.8.5)
meta_search (0.9.8, 0.9.7.2, 0.9.7.1, 0.9.6, 0.9.4)
mime-types (1.16)
mongo (1.1.2)
mongoid (2.0.0.beta.20)
multi_json (0.0.5)
multipart-post (1.0.1)
mysql (2.8.1)
mysql2 (0.2.6, 0.2.4, 0.2.3)
net-ldap (0.1.1)
nice-ffi (0.4)
nokogiri (1.4.4, 1.4.2)
oa-basic (0.1.6)
oa-core (0.1.6)
oa-enterprise (0.1.6)
oa-oauth (0.1.6)
oa-openid (0.1.6)
oauth (0.4.4, 0.4.3, 0.4.1)
oauth-plugin (0.4.0.pre1)
oauth2 (0.1.0)
omniauth (0.1.6)
paperclip (2.3.6, 2.3.4, 2.3.1.1)
passenger (2.2.12)
polyglot (0.3.1)
pyu-ruby-sasl (0.0.3.2)
querybuilder (0.9.2, 0.5.9)
rack (1.2.1, 1.1.0, 1.0.1)
rack-cache (0.5.3)
rack-cache-purge (0.0.2, 0.0.1)
rack-mount (0.6.13)
rack-openid (1.2.0)
rack-test (0.5.6, 0.5.4)
railroady (0.11.2)
rails (3.0.3, 3.0.1, 3.0.0, 3.0.0.rc2, 2.3.9, 2.3.5, 2.3.4)
railties (3.0.3, 3.0.1, 3.0.0, 3.0.0.rc2)
rake (0.8.7)
RedCloth (3.0.4)
rest-client (1.6.1)
roxml (3.1.5)
rscribd (1.2.0)
rspec (2.3.0, 2.2.0, 2.1.0, 2.0.1)
rspec-core (2.3.0, 2.2.1, 2.1.0, 2.0.1)
rspec-expectations (2.3.0, 2.2.0, 2.1.0, 2.0.1)
rspec-mocks (2.3.0, 2.2.0, 2.1.0, 2.0.1)
rspec-rails (2.3.0, 2.2.0, 2.1.0, 2.0.1)
ruby-hmac (0.4.0)
ruby-mysql (2.9.3)
ruby-ole (1.2.10.1)
ruby-openid (2.1.8)
ruby-openid-apps-discovery (1.2.0)
ruby-recaptcha (1.0.2, 1.0.0)
ruby-sdl-ffi (0.3)
ruby-termios (0.9.6)
ruby_parser (2.0.5)
rubyforge (2.0.4)
rubygame (2.6.4)
rubygems-update (1.3.7)
rubyless (0.7.0, 0.6.0, 0.3.5)
rubyntlm (0.1.1)
rubyzip2 (2.0.1)
scribd_fu (2.0.6)
searchlogic (2.4.27, 2.4.23)
sequel (3.16.0, 3.15.0, 3.13.0)
sexp_processor (3.0.5)
shoulda (2.11.3)
sinatra (1.0)
slim (0.8.0)
slim-rails (0.1.2)
spreadsheet (0.6.4.1)
sqlite3-ruby (1.3.2, 1.3.1)
ssl_requirement (0.1.0)
subdomain-fu (1.0.0.beta2, 0.5.4)
supermodel (0.1.4)
syntax (1.0.0)
taps (0.3.13, 0.3.11)
templater (1.0.0)
temple (0.1.6)
text-format (1.0.0)
text-hyphen (1.0.0)
thor (0.14.6, 0.14.4, 0.14.3, 0.14.1, 0.14.0)
tilt (1.1)
treetop (1.4.9, 1.4.8)
tzinfo (0.3.23)
uuidtools (2.1.1, 2.0.0)
validates_timeliness (3.0.0.beta.4, 2.3.1)
warden (0.10.7)
will_paginate (3.0.pre2, 2.3.15, 2.3.14)
xml-simple (1.0.12)
ya2yaml (0.30)
yajl-ruby (0.7.8, 0.7.7)
yamltest (0.7.0)
zena (0.16.9, 0.16.8)
======
I have ran sudo rvm implode and sudo rm -rf ~/.rvm, so no rvm now.
gem env
RubyGems Environment:
- RUBYGEMS VERSION: 1.3.7
- RUBY VERSION: 1.8.7 (2009-06-12 patchlevel 174) [i686-darwin10.2.0]
- INSTALLATION DIRECTORY: /usr/local/lib/ruby/gems/1.8
- RUBY EXECUTABLE: /usr/local/bin/ruby
- EXECUTABLE DIRECTORY: /usr/local/bin
- RUBYGEMS PLATFORMS:
- ruby
- x86-darwin-10
- GEM PATHS:
- /usr/local/lib/ruby/gems/1.8
- /Users/peter/.gem/ruby/1.8
- GEM CONFIGURATION:
- :update_sources => true
- :verbose => true
- :benchmark => false
- :backtrace => false
- :bulk_threshold => 1000
- :sources => ["http://rubygems.org/", "http://gems.github.com"]
- REMOTE SOURCES:
- http://rubygems.org/
- http://gems.github.com
===
ls -al /usr/local/lib/
total 5704
drwxr-xr-x 7 root wheel 238 Jun 1 2010 .
drwxr-xr-x 9 root wheel 306 Dec 15 16:20 ..
-rw-r--r-- 1 root wheel 1717208 Jun 1 2010 libruby-static.a
-rwxr-xr-x 1 root wheel 1191880 Jun 1 2010 libruby.1.8.7.dylib
lrwxrwxrwx 1 root wheel 19 Jun 1 2010 libruby.1.8.dylib -> libruby.1.8.7.dylib
lrwxrwxrwx 1 root wheel 19 Jun 1 2010 libruby.dylib -> libruby.1.8.7.dylib
drwxr-xr-x 6 root wheel 204 Jun 1 2010 ruby

Answer 1

Wow, um... you've been ... ah ... busy. Trying to clean things up will be a challenge and will probably be more than we can help with unless we can see into a lot of the system directories and your account's configuration.
My first question is: Have you made any changes to the system's default Ruby in /usr/bin/ruby? If so, I'd personally just back up the data I want to keep and wipe the drive and start over.
Have you run gem clean? That will remove a bunch of garbage, but will also probably raise a lot of questions about dependencies, and, when done, could leave things broken or unchanged - it's hard to say with that number of gems and revisions what will happen.
You can force gem to uninstall all the gems using something like:
gem list | awk '{print $1}' | xargs gem --all --quiet uninstall
Just be sure which Ruby version is running, because gem will act against the currently running Ruby. Use which ruby to find out.