diff --git a/lib/kgrader/cli.rb b/lib/kgrader/cli.rb
index 621e26b..e534587 100644
--- a/lib/kgrader/cli.rb
+++ b/lib/kgrader/cli.rb
@@ -9,8 +9,20 @@ module KGrader
     end
 
     def list
-      # TODO
-      puts "[list]"
+      @fs.courses.each do |name|
+        puts "course: #{name}"
+        course = Course.new(@fs, name)
+
+        puts "  rosters:"
+        course.rosters.each do |roster|
+          puts "    - #{roster.semester} (#{roster.students.size} students)"
+        end
+
+        puts "  assignments:"
+        course.assignments.each do |assignment|
+          puts "    - #{assignment}"
+        end
+      end
     end
 
     def roster(course, semester, rosterfile)
@@ -18,18 +30,15 @@ module KGrader
     end
 
     def grade(course, semester, assignment, options = {})
-      # TODO
-      # need to get default semester...
-      semester ||= 'DEFAULT'
-      task = Course.new(@fs, course).task semester, assignment
-      task.grade options
+      course = Course.new @fs, course
+      semester ||= course.current_semester
+      course.task(semester, assignment).grade options
     end
 
     def commit(course, semester, assignment, options = {})
-      # TODO
-      semester ||= 'DEFAULT'
-      task = Course.new(@fs, course).task semester, assignment
-      task.commit options
+      course = Course.new @fs, course
+      semester ||= course.current_semester
+      course.task(semester, assignment).commit options
     end
 
     def clean
diff --git a/lib/kgrader/course.rb b/lib/kgrader/course.rb
index c73d8c9..b6bd37f 100644
--- a/lib/kgrader/course.rb
+++ b/lib/kgrader/course.rb
@@ -20,5 +20,22 @@ module KGrader
       # TODO: cache
       Task.new @fs, self, semester, assignment
     end
+
+    def rosters
+      @fs.semesters(@name).map! { |semester| roster semester }
+    end
+
+    def assignments
+      @fs.assignments @name
+    end
+
+    def current_semester
+      case @config['semesters']
+      when 'faspYY'
+        KGrader::season + DateTime.now.strftime('%y')
+      when 'faspYYYY'
+        KGrader::season + DateTime.now.strftime('%Y')
+      end
+    end
   end
 end
diff --git a/lib/kgrader/filesystem.rb b/lib/kgrader/filesystem.rb
index ca38535..8e29759 100644
--- a/lib/kgrader/filesystem.rb
+++ b/lib/kgrader/filesystem.rb
@@ -7,8 +7,20 @@ module KGrader
       @root = root
     end
 
+    def desk
+      File.join @root, 'desk'
+    end
+
+    def jail
+      File.join @root, 'jail'
+    end
+
+    def spec
+      File.join @root, 'spec'
+    end
+
     def course(name)
-      File.join @root, 'spec', name
+      File.join spec, name
     end
 
     def course_config(name)
@@ -16,15 +28,19 @@ module KGrader
     end
 
     def courses
-      Dir[File.join @root, 'spec', '*', ''].each { |fn| File.basename fn }
+      Dir[File.join spec, '*', ''].map! { |fn| File.basename fn }
     end
 
-    def desk
-      File.join @root, 'desk'
+    def assignments(course)
+      Dir[File.join spec, course, '*', '_config.yml'].map! do |fn|
+        File.basename File.dirname fn
+      end
     end
 
-    def jail
-      File.join @root, 'jail'
+    def semesters(course)
+      Dir[File.join desk, course, '*', '_roster.csv'].map! do |fn|
+        File.basename File.dirname fn
+      end
     end
 
     def load(path)
diff --git a/lib/kgrader/roster.rb b/lib/kgrader/roster.rb
index faea976..108a5d4 100644
--- a/lib/kgrader/roster.rb
+++ b/lib/kgrader/roster.rb
@@ -1,5 +1,6 @@
 module KGrader
   class Roster
+    attr_reader :semester
 
     def initialize(filesystem, course, semester)
       @fs = filesystem
@@ -11,5 +12,10 @@ module KGrader
       # TODO
       puts "Loading roster for #{@course.name}:#{@semester} from [#{filename}]..."
     end
+
+    def students
+      # TODO
+      ["ksmith12"]
+    end
   end
 end
diff --git a/lib/kgrader/util.rb b/lib/kgrader/util.rb
index 07adbd0..9855047 100644
--- a/lib/kgrader/util.rb
+++ b/lib/kgrader/util.rb
@@ -33,4 +33,8 @@ module KGrader
     abort "too many arguments" if args.size > num
     return args, options
   end
+
+  def self.season
+    DateTime.now.strftime('%m').to_i <= 6 ? 'sp' : 'fa'
+  end
 end
diff --git a/spec/cs241h b/spec/cs241h
index 54398ad..3c6f5d0 160000
--- a/spec/cs241h
+++ b/spec/cs241h
@@ -1 +1 @@
-Subproject commit 54398ad4a16ac3d9f7344ecf680f4dd167e05818
+Subproject commit 3c6f5d050d8a66de6b3c36ce1985c225700a5c2f