diff --git a/050-env/050-env.go b/050-env/050-env.go
deleted file mode 100644
index 593bfec..0000000
--- a/050-env/050-env.go
+++ /dev/null
@@ -1,27 +0,0 @@
-package main                           // Use the `os` package to list, set, and get
-                                       // environment variables.
-import (
-    "os"
-    "fmt"
-    "strings"
-)
-
-func main() {
-    for _, e := range os.Environ() {   // `Environ` returns a slice of strings in the form
-        pair := strings.Split(e, "=")  // `KEY=value`. You can `strings.Split` them to get
-        fmt.Println(pair[0])           // the key and value.
-    }
-    fmt.Println()
-
-    os.Setenv("FOO", "bar")            // `Setenv` sets a given key, value pair.
-    fmt.Println(os.Getenv("FOO"))      // `Getenv` returns the value at key, or an empty
-}                                      // string if the key isn't present.
-
-/*
-$ go run env.go
-HOME
-PATH
-PWD
-...
-bar
-*/
diff --git a/050-env/env.go b/050-env/env.go
new file mode 100644
index 0000000..45a54e0
--- /dev/null
+++ b/050-env/env.go
@@ -0,0 +1,26 @@
+// ## Env
+
+package main                           
+
+// Use the `os` package to list, set, and get
+// environment variables.                                                           
+import "os"
+import "strings"
+import "fmt"
+
+func main() {
+    // `os.Environ` returns a slice of strings in the form
+    // `KEY=value`. You can `strings.Split` them to get
+    // the key and value.
+    for _, e := range os.Environ() {   
+        pair := strings.Split(e, "=")  
+        fmt.Println(pair[0])           
+    }
+    fmt.Println()
+
+    // `Setenv` sets a given key, value pair.
+    // `Getenv` returns the value at key, or an empty
+    // string if the key isn't present.
+    os.Setenv("FOO", "bar")            
+    fmt.Println(os.Getenv("FOO"))      
+}                                      
diff --git a/050-env/env.sh b/050-env/env.sh
new file mode 100644
index 0000000..968d927
--- /dev/null
+++ b/050-env/env.sh
@@ -0,0 +1,6 @@
+$ go run env.go
+HOME
+PATH
+PWD
+...
+bar
diff --git a/051-epoch/051-epoch.go b/051-epoch/051-epoch.go
deleted file mode 100644
index 44f1ea0..0000000
--- a/051-epoch/051-epoch.go
+++ /dev/null
@@ -1,20 +0,0 @@
-package main                    // Use `time.Now` with `Unix` or `UnixNane` to get
-                                // elapsed time since the Unix epoch.
-import "time"
-
-func main() {
-	now := time.Now()
-	secs := now.Unix()
-	nanos := now.UnixNano()
-	millis := nanos / 1000000   // There is no `UnixMillis`.
-	println("Secs:  ", secs)
-	println("Millis:", millis)
-	println("Nanos: ", nanos)
-}
-
-/*
-$ go run 051-epoch.go
-Secs:   1348240948
-Millis: 1348240948517
-Nanos:  1348240948517870000
-*/
diff --git a/051-epoch/epoch.go b/051-epoch/epoch.go
new file mode 100644
index 0000000..6eb3cc2
--- /dev/null
+++ b/051-epoch/epoch.go
@@ -0,0 +1,19 @@
+// ## Epoch
+
+package main                    
+                  
+import "time"
+
+func main() {
+    // Use `time.Now` with `Unix` or `UnixNane` to get
+    // elapsed time since the Unix epoch.
+	now := time.Now()
+	secs := now.Unix()
+	nanos := now.UnixNano()
+
+    // There is no `UnixMillis`.
+	millis := nanos / 1000000
+	println("Secs:  ", secs)
+	println("Millis:", millis)
+	println("Nanos: ", nanos)
+}
diff --git a/051-epoch/epoch.sh b/051-epoch/epoch.sh
new file mode 100644
index 0000000..2c1048c
--- /dev/null
+++ b/051-epoch/epoch.sh
@@ -0,0 +1,4 @@
+$ go run 051-epoch.go
+Secs:   1348240948
+Millis: 1348240948517
+Nanos:  1348240948517870000
diff --git a/052-errors/052-errors.go b/052-errors/errors.go
similarity index 78%
rename from 052-errors/052-errors.go
rename to 052-errors/errors.go
index 00f37c1..b78c3cd 100644
--- a/052-errors/052-errors.go
+++ b/052-errors/errors.go
@@ -1,3 +1,5 @@
+// ## Errors
+
 package main
 
 import ("fmt"; "errors")
@@ -18,6 +20,5 @@ func main() {
 	fmt.Println(e)
 }
 
-// == todo
-// custom errors
-// data conveying errors
+// todo: custom errors
+// todo: data conveying errors
diff --git a/053-exec/053-exec.go b/053-exec/exec.go
similarity index 79%
rename from 053-exec/053-exec.go
rename to 053-exec/exec.go
index 486f141..3cf232e 100644
--- a/053-exec/053-exec.go
+++ b/053-exec/exec.go
@@ -1,6 +1,10 @@
+// ## Exec
+
 package main
 
-import ("syscall"; "os"; "os/exec")
+import "syscall"
+import "os"
+import "os/exec"
 
 func main() {
 	binary, lookErr := exec.LookPath("ls")
diff --git a/054-exit/054-exit.go b/054-exit/054-exit.go
deleted file mode 100644
index ddfad46..0000000
--- a/054-exit/054-exit.go
+++ /dev/null
@@ -1,21 +0,0 @@
-package main            // Use `os.Exit` to immediatly exit with a given
-                        // status.
-import  "os"
-
-func main() {
-    defer println("!")  // This `println` will never be reached.
-	os.Exit(3)  
-}
-
-/*
-$ go run exit.go        // If you run `exit.go` using `go run`, the exit
-exit status 3           // will be picked up by `go` and printed.
-                        
-$ go build exit.go      // By building and executing a binary you can see
-$ ./exit                // the status in the terminal
-$ echo $?
-3
-*/
-
-// == todo
-// discuss building before getting here
diff --git a/054-exit/exit.go b/054-exit/exit.go
new file mode 100644
index 0000000..d8dec26
--- /dev/null
+++ b/054-exit/exit.go
@@ -0,0 +1,16 @@
+// Exit
+
+package main            
+
+// Use `os.Exit` to immediatly exit with a given
+// status.
+import  "os"
+
+func main() {
+    // This `println` will never be reached because the
+    // exit is immediate.
+    defer println("!")  
+	os.Exit(3)  
+}
+
+// todo: discuss building before getting here
diff --git a/054-exit/exit.sh b/054-exit/exit.sh
new file mode 100644
index 0000000..c3539ba
--- /dev/null
+++ b/054-exit/exit.sh
@@ -0,0 +1,11 @@
+#  If you run `exit.go` using `go run`, the exit
+# will be picked up by `go` and printed.
+$ go run exit.go
+exit status 3
+
+# By building and executing a binary you can see
+# the status in the terminal.
+$ go build exit.go
+$ ./exit
+$ echo $?
+3
diff --git a/055-file-open/055-file-open.go b/055-file-open/file-open.go
similarity index 86%
rename from 055-file-open/055-file-open.go
rename to 055-file-open/file-open.go
index 7dc5739..cd25a7a 100644
--- a/055-file-open/055-file-open.go
+++ b/055-file-open/file-open.go
@@ -1,6 +1,9 @@
+// ## File Open
+
 package main
 
-import ("fmt"; "os")
+import "os"
+import "fmt"
 
 func main() {
     file, err := os.Open("xx-file-open.go")
diff --git a/056-file-read/056-file-read.go b/056-file-read/file-read.go
similarity index 76%
rename from 056-file-read/056-file-read.go
rename to 056-file-read/file-read.go
index ef5369d..c636c8a 100644
--- a/056-file-read/056-file-read.go
+++ b/056-file-read/file-read.go
@@ -1,6 +1,9 @@
+// ## File Read
+
 package main
 
-import ("fmt"; "io/ioutil")
+import "io/ioutil"
+import "fmt"
 
 func main() {
     contents, err := ioutil.ReadFile("xx-file-read.go")
diff --git a/057-file-write/057-file-write.go b/057-file-write/file-write.go
similarity index 91%
rename from 057-file-write/057-file-write.go
rename to 057-file-write/file-write.go
index 8dd64df..f25b83d 100644
--- a/057-file-write/057-file-write.go
+++ b/057-file-write/file-write.go
@@ -1,3 +1,5 @@
+// ## File Write
+
 package main
 
 import "os"
diff --git a/058-flags/058-flags.go b/058-command-line-flags/command-line-flags.go
similarity index 55%
rename from 058-flags/058-flags.go
rename to 058-command-line-flags/command-line-flags.go
index e154258..64a8092 100644
--- a/058-flags/058-flags.go
+++ b/058-command-line-flags/command-line-flags.go
@@ -1,6 +1,9 @@
+// ## Command Line Flags
+
 package main
 
-import ("fmt"; "flag")
+import "flag"
+import "fmt"
 
 func main() {
     maxp := flag.Int("repeat", 3, "time to repeat args")
@@ -12,8 +15,7 @@ func main() {
 	}
 }
 
-// todoo
-// multiple flags
-// trailing args
-// arg escaping
-// help text and usage errors
+// todo: multiple flags
+// todo: trailing args
+// todo: arg escaping
+// todo: help text and usage errors
diff --git a/059-http-client-basic/059-http-client-basic.go b/059-http-client-basic/http-client-basic.go
similarity index 81%
rename from 059-http-client-basic/059-http-client-basic.go
rename to 059-http-client-basic/http-client-basic.go
index b48a850..06531cc 100644
--- a/059-http-client-basic/059-http-client-basic.go
+++ b/059-http-client-basic/http-client-basic.go
@@ -1,6 +1,10 @@
+// ## HTTP Client Basic Auth
+
 package main
 
-import ("net/http"; "io/ioutil"; "fmt")
+import "net/http"
+import "io/ioutil"
+import "fmt"
 
 func main() {
 	req, _ := http.NewRequest("GET", "http://127.0.0.1:5000/", nil)
diff --git a/060-http-client/060-http-client.go b/060-http-client/http-client.go
similarity index 74%
rename from 060-http-client/060-http-client.go
rename to 060-http-client/http-client.go
index a2c6b39..79a043b 100644
--- a/060-http-client/060-http-client.go
+++ b/060-http-client/http-client.go
@@ -1,6 +1,10 @@
+// ## HTTP Client
+
 package main
 
-import ("net/http"; "io/ioutil"; "fmt")
+import "net/http"
+import "io/ioutil"
+import "fmt"
 
 func main() {
 	resp, err := http.Get("http://127.0.0.1:5000/")
diff --git a/061-http-server-basic/061-http-server-basic.go b/061-http-server-basic/http-server-basic.go
similarity index 97%
rename from 061-http-server-basic/061-http-server-basic.go
rename to 061-http-server-basic/http-server-basic.go
index 531d110..8b6d811 100644
--- a/061-http-server-basic/061-http-server-basic.go
+++ b/061-http-server-basic/http-server-basic.go
@@ -1,10 +1,12 @@
+// ## HTTP Server Basic
+
 package main
 
 import (
-	"fmt"
 	"net/http"
 	"encoding/base64"
 	"strings"
+	"fmt"
 )
 
 type Authenticator func(string, string) bool
diff --git a/tool/index.txt b/tool/index.txt
index aa79407..c8b3140 100644
--- a/tool/index.txt
+++ b/tool/index.txt
@@ -55,7 +55,7 @@ exit
 file-open
 file-read
 file-write
-flags
+command-line-flags
 http-client-basic
 http-client
 http-server-basic