diff --git a/cmd/commandfuncs.go b/cmd/commandfuncs.go
index be9da93c..715f064d 100644
--- a/cmd/commandfuncs.go
+++ b/cmd/commandfuncs.go
@@ -26,6 +26,8 @@ import (
 	"net/http"
 	"os"
 	"os/exec"
+	"reflect"
+	"runtime/debug"
 	"strings"
 
 	"github.com/caddyserver/caddy/v2"
@@ -36,7 +38,7 @@ import (
 
 func cmdStart(fl Flags) (int, error) {
 	startCmdConfigFlag := fl.String("config")
-	startCmdConfigAdapterFlag := fl.String("config-adapter")
+	startCmdConfigAdapterFlag := fl.String("adapter")
 
 	// open a listener to which the child process will connect when
 	// it is ready to confirm that it has successfully started
@@ -61,7 +63,7 @@ func cmdStart(fl Flags) (int, error) {
 		cmd.Args = append(cmd.Args, "--config", startCmdConfigFlag)
 	}
 	if startCmdConfigAdapterFlag != "" {
-		cmd.Args = append(cmd.Args, "--config-adapter", startCmdConfigAdapterFlag)
+		cmd.Args = append(cmd.Args, "--adapter", startCmdConfigAdapterFlag)
 	}
 	stdinpipe, err := cmd.StdinPipe()
 	if err != nil {
@@ -137,8 +139,8 @@ func cmdStart(fl Flags) (int, error) {
 
 func cmdRun(fl Flags) (int, error) {
 	runCmdConfigFlag := fl.String("config")
-	runCmdConfigAdapterFlag := fl.String("config-adapter")
-	runCmdPrintEnvFlag := fl.Bool("print-env")
+	runCmdConfigAdapterFlag := fl.String("adapter")
+	runCmdPrintEnvFlag := fl.Bool("environ")
 	runCmdPingbackFlag := fl.String("pingback")
 
 	// if we are supposed to print the environment, do that first
@@ -216,7 +218,7 @@ func cmdStop(_ Flags) (int, error) {
 
 func cmdReload(fl Flags) (int, error) {
 	reloadCmdConfigFlag := fl.String("config")
-	reloadCmdConfigAdapterFlag := fl.String("config-adapter")
+	reloadCmdConfigAdapterFlag := fl.String("adapter")
 	reloadCmdAddrFlag := fl.String("address")
 
 	// a configuration is required
@@ -282,10 +284,61 @@ func cmdVersion(_ Flags) (int, error) {
 	return caddy.ExitCodeSuccess, nil
 }
 
-func cmdListModules(_ Flags) (int, error) {
-	for _, m := range caddy.Modules() {
-		fmt.Println(m)
+func cmdListModules(fl Flags) (int, error) {
+	versions := fl.Bool("versions")
+
+	bi, ok := debug.ReadBuildInfo()
+	if !ok || !versions {
+		// if there's no build information,
+		// just print out the modules
+		for _, m := range caddy.Modules() {
+			fmt.Println(m)
+		}
+		return caddy.ExitCodeSuccess, nil
 	}
+
+	for _, modName := range caddy.Modules() {
+		modInfo, err := caddy.GetModule(modName)
+		if err != nil {
+			// that's weird
+			fmt.Println(modName)
+			continue
+		}
+
+		// to get the Caddy plugin's version info, we need to know
+		// the package that the Caddy module's value comes from; we
+		// can use reflection but we need a non-pointer value (I'm
+		// not sure why), and since New() should return a pointer
+		// value, we need to dereference it first
+		iface := interface{}(modInfo.New())
+		if rv := reflect.ValueOf(iface); rv.Kind() == reflect.Ptr {
+			iface = reflect.New(reflect.TypeOf(iface).Elem()).Elem().Interface()
+		}
+		modPkgPath := reflect.TypeOf(iface).PkgPath()
+
+		// now we find the Go module that the Caddy module's package
+		// belongs to; we assume the Caddy module package path will
+		// be prefixed by its Go module path, and we will choose the
+		// longest matching prefix in case there are nested modules
+		var matched *debug.Module
+		for _, dep := range bi.Deps {
+			if strings.HasPrefix(modPkgPath, dep.Path) {
+				if matched == nil || len(dep.Path) > len(matched.Path) {
+					matched = dep
+				}
+			}
+		}
+
+		// if we could find no matching module, just print out
+		// the module name instead
+		if matched == nil {
+			fmt.Println(modName)
+			continue
+		}
+
+		fmt.Printf("%s %s\n", modName, matched.Version)
+	}
+
 	return caddy.ExitCodeSuccess, nil
 }
 
@@ -295,13 +348,13 @@ func cmdEnviron(_ Flags) (int, error) {
 }
 
 func cmdAdaptConfig(fl Flags) (int, error) {
+	adaptCmdInputFlag := fl.String("config")
 	adaptCmdAdapterFlag := fl.String("adapter")
-	adaptCmdInputFlag := fl.String("input")
 	adaptCmdPrettyFlag := fl.Bool("pretty")
 
 	if adaptCmdAdapterFlag == "" || adaptCmdInputFlag == "" {
 		return caddy.ExitCodeFailedStartup,
-			fmt.Errorf("usage: caddy adapt-config --adapter <name> --input <file>")
+			fmt.Errorf("usage: caddy adapt --adapter <name> --input <file>")
 	}
 
 	cfgAdapter := caddyconfig.GetAdapter(adaptCmdAdapterFlag)
@@ -341,6 +394,55 @@ func cmdAdaptConfig(fl Flags) (int, error) {
 	return caddy.ExitCodeSuccess, nil
 }
 
+func cmdValidateConfig(fl Flags) (int, error) {
+	validateCmdConfigFlag := fl.String("config")
+	validateCmdAdapterFlag := fl.String("adapter")
+
+	input, err := ioutil.ReadFile(validateCmdConfigFlag)
+	if err != nil {
+		return caddy.ExitCodeFailedStartup,
+			fmt.Errorf("reading input file: %v", err)
+	}
+
+	if validateCmdAdapterFlag != "" {
+		cfgAdapter := caddyconfig.GetAdapter(validateCmdAdapterFlag)
+		if cfgAdapter == nil {
+			return caddy.ExitCodeFailedStartup,
+				fmt.Errorf("unrecognized config adapter: %s", validateCmdAdapterFlag)
+		}
+
+		adaptedConfig, warnings, err := cfgAdapter.Adapt(input, nil)
+		if err != nil {
+			return caddy.ExitCodeFailedStartup, err
+		}
+		// print warnings to stderr
+		for _, warn := range warnings {
+			msg := warn.Message
+			if warn.Directive != "" {
+				msg = fmt.Sprintf("%s: %s", warn.Directive, warn.Message)
+			}
+			log.Printf("[WARNING][%s] %s:%d: %s", validateCmdAdapterFlag, warn.File, warn.Line, msg)
+		}
+
+		input = adaptedConfig
+	}
+
+	var cfg *caddy.Config
+	err = json.Unmarshal(input, &cfg)
+	if err != nil {
+		return caddy.ExitCodeFailedStartup, fmt.Errorf("decoding config: %v", err)
+	}
+
+	err = caddy.Validate(cfg)
+	if err != nil {
+		return caddy.ExitCodeFailedStartup, err
+	}
+
+	fmt.Println("Valid configuration")
+
+	return caddy.ExitCodeSuccess, nil
+}
+
 func cmdHelp(fl Flags) (int, error) {
 	const fullDocs = `Full documentation is available at:
 https://github.com/caddyserver/caddy/wiki/v2:-Documentation`
diff --git a/cmd/commands.go b/cmd/commands.go
index 8a9d4824..731e8139 100644
--- a/cmd/commands.go
+++ b/cmd/commands.go
@@ -54,7 +54,7 @@ var commands = map[string]Command{
 	"start": {
 		Name:  "start",
 		Func:  cmdStart,
-		Usage: "[--config <path>] [--config-adapter <name>]",
+		Usage: "[--config <path>] [--adapter <name>]",
 		Short: "Starts the Caddy process and returns after server has started.",
 		Long: `
 Starts the Caddy process, optionally bootstrapped with an initial
@@ -65,7 +65,7 @@ details.`,
 		Flags: func() *flag.FlagSet {
 			fs := flag.NewFlagSet("start", flag.ExitOnError)
 			fs.String("config", "", "Configuration file")
-			fs.String("config-adapter", "", "Name of config adapter to apply")
+			fs.String("adapter", "", "Name of config adapter to apply")
 			return fs
 		}(),
 	},
@@ -73,7 +73,7 @@ details.`,
 	"run": {
 		Name:  "run",
 		Func:  cmdRun,
-		Usage: "[--config <path>] [--config-adapter <name>] [--print-env]",
+		Usage: "[--config <path>] [--adapter <name>] [--print-env]",
 		Short: `Starts the Caddy process and blocks indefinitely.`,
 		Long: `
 Same as start, but blocks indefinitely; i.e. runs Caddy in "daemon" mode. On
@@ -83,25 +83,25 @@ window.
 
 If a config file is specified, it will be applied immediately after the process
 is running. If the config file is not in Caddy's native JSON format, you can
-specify an adapter with --config-adapter to adapt the given config file to
+specify an adapter with --adapter to adapt the given config file to
 Caddy's native format. The config adapter must be a registered module. Any
 warnings will be printed to the log, but beware that any adaptation without
 errors will immediately be used. If you want to review the results of the
-adaptation first, use adapt-config.
+adaptation first, use the 'adapt' subcommand.
 
 As a special case, if the current working directory has a file called
 "Caddyfile" and the caddyfile config adapter is plugged in (default), then that
 file will be loaded and used to configure Caddy, even without any command line
 flags.
 
-If --print-env is specified, the environment as seen by the Caddy process will
+If --environ is specified, the environment as seen by the Caddy process will
 be printed before starting. This is the same as the environ command but does
 not quit after printing.`,
 		Flags: func() *flag.FlagSet {
 			fs := flag.NewFlagSet("run", flag.ExitOnError)
 			fs.String("config", "", "Configuration file")
-			fs.String("config-adapter", "", "Name of config adapter to apply")
-			fs.Bool("print-env", false, "Print environment")
+			fs.String("adapter", "", "Name of config adapter to apply")
+			fs.Bool("environ", false, "Print environment")
 			fs.String("pingback", "", "Echo confirmation bytes to this address on success")
 			return fs
 		}(),
@@ -120,7 +120,7 @@ shutdown on Windows, use Ctrl+C or the /stop endpoint.`,
 	"reload": {
 		Name:  "reload",
 		Func:  cmdReload,
-		Usage: "--config <path> [--config-adapter <name>] [--address <interface>]",
+		Usage: "--config <path> [--adapter <name>] [--address <interface>]",
 		Short: "Gives the running Caddy instance a new configuration",
 		Long: `Gives the running Caddy instance a new configuration. This has the same effect
 as POSTing a document to the /load endpoint, but is convenient for simple
@@ -129,9 +129,9 @@ configurable, the endpoint configuration is loaded from the --address flag if
 specified; otherwise it is loaded from the given config file; otherwise the
 default is assumed.`,
 		Flags: func() *flag.FlagSet {
-			fs := flag.NewFlagSet("load", flag.ExitOnError)
+			fs := flag.NewFlagSet("reload", flag.ExitOnError)
 			fs.String("config", "", "Configuration file")
-			fs.String("config-adapter", "", "Name of config adapter to apply")
+			fs.String("adapter", "", "Name of config adapter to apply")
 			fs.String("address", "", "Address of the administration listener, if different from config")
 			return fs
 		}(),
@@ -149,6 +149,11 @@ default is assumed.`,
 		Func:  cmdListModules,
 		Short: "List installed Caddy modules.",
 		Long:  `List installed Caddy modules.`,
+		Flags: func() *flag.FlagSet {
+			fs := flag.NewFlagSet("list-modules", flag.ExitOnError)
+			fs.Bool("versions", false, "Print version information")
+			return fs
+		}(),
 	},
 
 	"environ": {
@@ -158,15 +163,38 @@ default is assumed.`,
 		Long:  `Prints the environment as seen by Caddy.`,
 	},
 
-	"adapt-config": {
-		Name:  "adapt-config",
+	"adapt": {
+		Name:  "adapt",
 		Func:  cmdAdaptConfig,
-		Usage: "--input <path> --adapter <name> [--pretty]",
+		Usage: "--config <path> --adapter <name> [--pretty]",
 		Short: "Adapts a configuration to Caddy's native JSON config structure",
 		Long: `
 Adapts a configuration to Caddy's native JSON config structure and writes the
 output to stdout, along with any warnings to stderr. If --pretty is specified,
 the output will be formatted with indentation for human readability.`,
+		Flags: func() *flag.FlagSet {
+			fs := flag.NewFlagSet("adapt", flag.ExitOnError)
+			fs.String("config", "", "Configuration file to adapt")
+			fs.String("adapter", "", "Name of config adapter")
+			fs.Bool("pretty", false, "Format the output for human readability")
+			return fs
+		}(),
+	},
+
+	"validate": {
+		Name:  "validate",
+		Func:  cmdValidateConfig,
+		Usage: "--config <path> [--adapter <name>]",
+		Short: "Tests whether a configuration file is valid.",
+		Long: `
+Loads and provisions the provided config, but does not start
+running it.`,
+		Flags: func() *flag.FlagSet {
+			fs := flag.NewFlagSet("load", flag.ExitOnError)
+			fs.String("config", "", "Input configuration file")
+			fs.String("adapter", "", "Name of config adapter")
+			return fs
+		}(),
 	},
 }