A1) Without merb-extlib

require 'rubygems'
# require 'merb-extlib'

p $LOADED_FEATURES

A2) Results

["enumerator.so", "pathname.rb", "catch_exception.rb", "English.rb", "/Applications/TextMate.app/Contents/SharedSupport/Support/lib/escape.rb", "/Applications/TextMate.app/Contents/SharedSupport/Support/lib/osx/plist.bundle", "/Applications/TextMate.app/Contents/SharedSupport/Support/lib/ui.rb", "io/wait.bundle", "stdin_dialog.rb", "rubygems/rubygems_version.rb", "rubygems/defaults.rb", "thread.bundle", "thread.rb", "rbconfig.rb", "rubygems/exceptions.rb", "rubygems/requirement.rb", "rubygems/version.rb", "rubygems/dependency.rb", "rubygems/gem_path_searcher.rb", "rubygems/user_interaction.rb", "rubygems/platform.rb", "rubygems/specification.rb", "zlib.bundle", "socket.bundle", "timeout.rb", "net/protocol.rb", "uri/common.rb", "uri/generic.rb", "uri/ftp.rb", "uri/http.rb", "uri/https.rb", "uri/ldap.rb", "uri/ldaps.rb", "uri/mailto.rb", "uri.rb", "net/http.rb", "stringio.bundle", "rubygems/remote_fetcher.rb", "rubygems/spec_fetcher.rb", "rubygems/source_index.rb", "rubygems/builder.rb", "rubygems/custom_require.rb", "rubygems.rb"]

B1) With merb-extlib

require 'rubygems'
require 'merb-extlib'

p $LOADED_FEATURES

B2) Results

["enumerator.so", "pathname.rb", "catch_exception.rb", "English.rb", "/Applications/TextMate.app/Contents/SharedSupport/Support/lib/escape.rb", "/Applications/TextMate.app/Contents/SharedSupport/Support/lib/osx/plist.bundle", "/Applications/TextMate.app/Contents/SharedSupport/Support/lib/ui.rb", "io/wait.bundle", "stdin_dialog.rb", "rubygems/rubygems_version.rb", "rubygems/defaults.rb", "thread.bundle", "thread.rb", "rbconfig.rb", "rubygems/exceptions.rb", "rubygems/requirement.rb", "rubygems/version.rb", "rubygems/dependency.rb", "rubygems/gem_path_searcher.rb", "rubygems/user_interaction.rb", "rubygems/platform.rb", "rubygems/specification.rb", "zlib.bundle", "socket.bundle", "timeout.rb", "net/protocol.rb", "uri/common.rb", "uri/generic.rb", "uri/ftp.rb", "uri/http.rb", "uri/https.rb", "uri/ldap.rb", "uri/ldaps.rb", "uri/mailto.rb", "uri.rb", "net/http.rb", "stringio.bundle", "rubygems/remote_fetcher.rb", "rubygems/spec_fetcher.rb", "rubygems/source_index.rb", "rubygems/builder.rb", "rubygems/custom_require.rb", "rubygems.rb", "etc.bundle", "fileutils.rb", "/usr/local/lib/ruby/gems/1.8/gems/merb-extlib-0.9.4/lib/merb-extlib/pathname.rb", "/usr/local/lib/ruby/gems/1.8/gems/merb-extlib-0.9.4/lib/merb-extlib/version.rb", "/usr/local/lib/ruby/gems/1.8/gems/merb-extlib-0.9.4/lib/merb-extlib/string.rb", "/usr/local/lib/ruby/gems/1.8/gems/merb-extlib-0.9.4/lib/merb-extlib/time.rb", "/usr/local/lib/ruby/gems/1.8/gems/merb-extlib-0.9.4/lib/merb-extlib/class.rb", "nkf.bundle", "kconv.rb", "base64.rb", "rexml/parsers/streamparser.rb", "rexml/parseexception.rb", "rexml/undefinednamespaceexception.rb", "rexml/encoding.rb", "rexml/source.rb", "set.rb", "rexml/parsers/baseparser.rb", "rexml/xmltokens.rb", "rexml/light/node.rb", "/usr/local/lib/ruby/gems/1.8/gems/merb-extlib-0.9.4/lib/merb-extlib/hash.rb", "/usr/local/lib/ruby/gems/1.8/gems/merb-extlib-0.9.4/lib/merb-extlib/mash.rb", "/usr/local/lib/ruby/gems/1.8/gems/merb-extlib-0.9.4/lib/merb-extlib/object.rb", "/usr/local/lib/ruby/gems/1.8/gems/merb-extlib-0.9.4/lib/merb-extlib/object_space.rb", "/usr/local/lib/ruby/gems/1.8/gems/merb-extlib-0.9.4/lib/merb-extlib/rubygems.rb", "/usr/local/lib/ruby/gems/1.8/gems/merb-extlib-0.9.4/lib/merb-extlib/set.rb", "/usr/local/lib/ruby/gems/1.8/gems/merb-extlib-0.9.4/lib/merb-extlib/virtual_file.rb", "rational.rb", "date/format.rb", "parsedate.rb", "time.rb", "/usr/local/lib/ruby/gems/1.8/gems/merb-extlib-0.9.4/lib/merb-extlib/logger.rb", "merb-extlib.rb"]