diff --git a/main.go b/main.go
index 1f3b133..cc86dab 100644
--- a/main.go
+++ b/main.go
@@ -1,118 +1,178 @@
 package main
 
 import (
-	"archive/zip"
+	"encoding/json"
 	"fmt"
 	"os"
-	"strings"
 )
 
 type Command struct {
 	Name        string
 	Description string
-	Action      func([]string) Result
+	Action      func([]string) (string, error)
 	Arguments   []string
 	IsVarargs   bool
 }
 
-func Failed(message string) Result {
-	return Result{
-		HasFailed: true,
-		Message:   message,
-	}
-}
-
-func Ok(message string) Result {
-	return Result{
-		HasFailed: false,
-		Message:   message,
-	}
-}
-
-type Result struct {
-	Message   string
-	HasFailed bool
-}
-
 var commands = []Command{
 	{
 		Name:        "install",
 		Description: "Install one or more mod archives into modman",
-		Arguments:   []string{"archive path"},
+		Arguments:   []string{"game name", "archive path"},
 		IsVarargs:   true,
 
-		Action: func(arguments []string) Result {
-			var processed = 0
+		Action: func(arguments []string) (string, error) {
+			var argumentCount = len(arguments)
 
-			for i := range arguments {
-				var archivePath = arguments[i]
-
-				if strings.HasSuffix(archivePath, ".zip") {
-					var reader, err = zip.OpenReader(archivePath)
-
-					if err == nil {
-						defer reader.Close()
-
-						processed += 1
-					}
-
-					continue
-				}
+			if argumentCount == 0 {
+				return "", fmt.Errorf("expected game name")
 			}
 
-			return Ok(fmt.Sprint(processed, "of", len(arguments), "installed"))
+			var modsToInstall = arguments[1:]
+			var installedMods = []string{}
+
+			if gameError := WithGame(arguments[0], func(game *Game) error {
+				var installed, installError = game.InstallMods(modsToInstall)
+
+				if installError != nil {
+					return installError
+				}
+
+				installedMods = installed
+
+				return nil
+			}); gameError != nil {
+				return "", gameError
+			}
+
+			return fmt.Sprint(len(installedMods), " of ", len(modsToInstall), " installed"), nil
 		},
 	},
 
 	{
 		Name:        "remove",
 		Description: "Remove one or more mods from modman",
-		Arguments:   []string{"mod name"},
+		Arguments:   []string{"game name", "mod name"},
 		IsVarargs:   true,
 
-		Action: func(arguments []string) Result {
-			// TODO: Implement.
-			return Failed("Not implemented")
+		Action: func(arguments []string) (string, error) {
+			var argumentCount = len(arguments)
+
+			if argumentCount == 0 {
+				return "", fmt.Errorf("expected game name")
+			}
+
+			var modsToRemove = arguments[1:]
+			var removedMods = []string{}
+
+			if gameError := WithGame(arguments[0], func(game *Game) error {
+				var removed, removeError = game.RemoveMods(modsToRemove)
+
+				if removeError != nil {
+					return removeError
+				}
+
+				removedMods = removed
+
+				return nil
+			}); gameError != nil {
+				return "", gameError
+			}
+
+			return fmt.Sprint(len(removedMods), " of ", len(removedMods), " removed"), nil
 		},
 	},
 
 	{
 		Name:        "rename",
 		Description: "Rename a mod within modman",
-		Arguments:   []string{"mod name", "new name"},
+		Arguments:   []string{"game name", "mod name", "new name"},
 		IsVarargs:   false,
 
-		Action: func(arguments []string) Result {
-			// TODO: Implement.
-			return Failed("Not implemented")
+		Action: func(arguments []string) (string, error) {
+			if len(arguments) != 3 {
+				return "", fmt.Errorf("expected game name followed by mod name and new name")
+			}
+
+			if gameError := WithGame(arguments[0], func(game *Game) error {
+				if removeError := game.RenameMod(arguments[1], arguments[2]); removeError != nil {
+					return removeError
+				}
+
+				return nil
+			}); gameError != nil {
+				return "", gameError
+			}
+
+			return "", nil
 		},
 	},
 
 	{
-		Name:        "list",
-		Description: "List all installed mods",
-		Arguments:   []string{},
+		Name:        "manifest",
+		Description: "Retrieve a manifest of all installed mods",
+		Arguments:   []string{"game name", "format"},
 		IsVarargs:   false,
 
-		Action: func(arguments []string) Result {
-			// TODO: Implement.
-			return Failed("Not implemented")
+		Action: func(arguments []string) (string, error) {
+			if len(arguments) != 2 {
+				return "", fmt.Errorf("expected game name followed by format")
+			}
+
+			var modManifest = ""
+
+			if gameError := WithGame(arguments[0], func(game *Game) error {
+				var format = arguments[1]
+				var formatter, formatterExists = formatters[format]
+
+				if !(formatterExists) {
+					return fmt.Errorf("unsupported format: `%s`", format)
+				}
+
+				var formattedManifest, formatError = formatter(game.Mods)
+
+				if formatError != nil {
+					return formatError
+				}
+
+				// TODO: Reconsider if always casting formatted data to string for output is a good
+				// idea.
+				modManifest = string(formattedManifest)
+
+				return nil
+			}); gameError != nil {
+				return "", gameError
+			}
+
+			return modManifest, nil
 		},
 	},
 
 	{
 		Name:        "deploy",
 		Description: "Deploy all installed and enabled mods",
-		Arguments:   []string{},
+		Arguments:   []string{"game name"},
 		IsVarargs:   false,
 
-		Action: func(arguments []string) Result {
+		Action: func(arguments []string) (string, error) {
 			// TODO: Implement.
-			return Failed("Not implemented")
+			return "", fmt.Errorf("not implemented")
 		},
 	},
 }
 
+var formatters = map[string]func(any) ([]byte, error){
+	"json": func(data any) ([]byte, error) {
+		var marshalledJson, marshalError = json.Marshal(data)
+
+		if marshalError != nil {
+			return nil, marshalError
+		}
+
+		return marshalledJson, nil
+	},
+}
+
 func main() {
 	var argCount = len(os.Args)
 
@@ -145,16 +205,20 @@ func main() {
 		var command = commands[i]
 
 		if command.Name == commandName {
-			var result = command.Action(os.Args[2:])
+			var response, actionError = command.Action(os.Args[2:])
 
-			if result.HasFailed {
-				fmt.Fprint(os.Stderr, result.Message)
+			if actionError != nil {
+				fmt.Fprintln(os.Stderr, actionError.Error())
 				os.Exit(1)
 			}
 
-			fmt.Print(result.Message)
+			if len(response) != 0 {
+				fmt.Println(response)
+			}
 
 			return
 		}
 	}
+
+	fmt.Fprintf(os.Stderr, "unknown command: `%s`\n", commandName)
 }
diff --git a/manager.go b/manager.go
new file mode 100644
index 0000000..f6fba97
--- /dev/null
+++ b/manager.go
@@ -0,0 +1,290 @@
+package main
+
+import (
+	"archive/zip"
+	"encoding/csv"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+type App struct {
+	ConfigDirPath string
+}
+
+type Game struct {
+	ID         string
+	Mods       map[string]Mod
+	HasUpdated bool
+}
+
+func (game *Game) InstallMods(archivePaths []string) ([]string, error) {
+	var processed = 0
+
+	for i := range archivePaths {
+		var archivePath = archivePaths[i]
+		var suffixIndex = strings.LastIndex(archivePath, ".")
+
+		if suffixIndex < 0 {
+			return nil, fmt.Errorf("cannot determine file type of `%s`", archivePath)
+		}
+
+		var extension = archivePath[suffixIndex+1:]
+		var extractor = extractors[extension]
+
+		if extractor == nil {
+			return nil, fmt.Errorf("unsupported file type `%s`", extension)
+		}
+
+		var gamePath, pathError = game.Path()
+
+		if pathError != nil {
+			return nil, pathError
+		}
+
+		var modName = filepath.Base(archivePath[:suffixIndex])
+
+		if extractError := extractor(archivePath, filepath.Join(
+			gamePath, "mods", modName)); extractError != nil {
+
+			return nil, extractError
+		}
+
+		game.Mods[modName] = Mod{
+			IsEnabled: false,
+		}
+
+		game.HasUpdated = true
+		processed += 1
+	}
+
+	return archivePaths[0:processed], nil
+}
+
+type Mod struct {
+	IsEnabled bool
+}
+
+func WithGame(gameName string, action func(*Game) error) error {
+	var supportedGames = []string{"fallout4", "falloutnv", "skyrim"}
+
+	for i := range supportedGames {
+		var supportedGame = supportedGames[i]
+
+		if gameName == supportedGame {
+			var game = Game{
+				ID:         supportedGame,
+				Mods:       make(map[string]Mod),
+				HasUpdated: false,
+			}
+
+			var gamePath, pathError = game.Path()
+
+			if pathError != nil {
+				return pathError
+			}
+
+			var manifestPath = filepath.Join(gamePath, "mods.csv")
+
+			// Load manifest from disk.
+			{
+				var manifestFile, openError = os.Open(manifestPath)
+
+				if openError == nil {
+					defer manifestFile.Close()
+
+					var manifestReader = csv.NewReader(manifestFile)
+					var recordValues, recordError = manifestReader.Read()
+
+					for recordValues != nil {
+						if recordError != nil {
+							return recordError
+						}
+
+						if len(recordValues) < 2 {
+							return fmt.Errorf("could not read mod manifest data - may be corrupt")
+						}
+
+						var status = recordValues[0]
+						var name = recordValues[1]
+
+						game.Mods[name] = Mod{
+							IsEnabled: status == "*",
+						}
+
+						recordValues, recordError = manifestReader.Read()
+					}
+				}
+			}
+
+			if actionError := action(&game); actionError != nil {
+				return actionError
+			}
+
+			// Save manifest back to disk.
+			if game.HasUpdated {
+				var manifestFile, openError = os.OpenFile(manifestPath,
+					os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
+
+				if openError != nil {
+					return openError
+				}
+
+				defer manifestFile.Close()
+
+				var manifestWriter = csv.NewWriter(manifestFile)
+
+				for name, mod := range game.Mods {
+					var status = ""
+
+					if mod.IsEnabled {
+						status = "*"
+					}
+
+					manifestWriter.Write([]string{status, name})
+				}
+
+				manifestWriter.Flush()
+			}
+
+			return nil
+		}
+	}
+
+	return fmt.Errorf("%s: game not supported", gameName)
+}
+
+func (game Game) Path() (string, error) {
+	var configDirPath, configError = os.UserConfigDir()
+
+	if configError != nil {
+		return "", configError
+	}
+
+	return filepath.Join(configDirPath, "modman", game.ID), nil
+}
+
+func (game *Game) RemoveMods(modNames []string) ([]string, error) {
+	var gamePath, pathError = game.Path()
+
+	if pathError != nil {
+		return nil, pathError
+	}
+
+	var processed = 0
+
+	for i := range modNames {
+		var modName = modNames[i]
+
+		if removeError := os.RemoveAll(filepath.Join(gamePath, modName)); removeError != nil {
+			return nil, removeError
+		}
+
+		delete(game.Mods, modName)
+
+		game.HasUpdated = true
+		processed += 1
+	}
+
+	return modNames[0:processed], nil
+}
+
+func (game *Game) RenameMod(modName string, newName string) error {
+	var gamePath, pathError = game.Path()
+
+	if pathError != nil {
+		return pathError
+	}
+
+	if _, exists := game.Mods[modName]; !(exists) {
+		return fmt.Errorf("no mod with that name exists")
+	}
+
+	if _, exists := game.Mods[newName]; exists {
+		return fmt.Errorf("a mod with the new name already exists")
+	}
+
+	if renameError := os.Rename(filepath.Join(gamePath, modName),
+		filepath.Join(gamePath, newName)); renameError != nil {
+
+		return renameError
+	}
+
+	game.Mods[newName] = game.Mods[modName]
+
+	delete(game.Mods, modName)
+
+	game.HasUpdated = true
+
+	return nil
+}
+
+var extractors = map[string]func(string, string) error{
+	"zip": func(archivePath string, destinationPath string) error {
+		var zipReader, openReaderError = zip.OpenReader(archivePath)
+
+		if openReaderError != nil {
+			return openReaderError
+		}
+
+		defer func() {
+			if closeError := zipReader.Close(); closeError != nil {
+				panic(closeError.Error())
+			}
+		}()
+
+		if mkdirError := os.MkdirAll(destinationPath, 0755); mkdirError != nil {
+			return mkdirError
+		}
+
+		for i := range zipReader.File {
+			var file = zipReader.File[i]
+			var fileReader, fileOpenError = file.Open()
+
+			if fileOpenError != nil {
+				return fileOpenError
+			}
+
+			defer func() {
+				if closeError := fileReader.Close(); closeError != nil {
+					panic(closeError.Error())
+				}
+			}()
+
+			var path = filepath.Join(destinationPath, file.Name)
+
+			if file.FileInfo().IsDir() {
+				if mkdirError := os.MkdirAll(path, file.Mode()); mkdirError != nil {
+					return mkdirError
+				}
+			} else {
+				if mkdirError := os.MkdirAll(filepath.Dir(path), file.Mode()); mkdirError != nil {
+					return mkdirError
+				}
+
+				var extractedFile, fileOpenError = os.OpenFile(path,
+					os.O_WRONLY|os.O_CREATE|os.O_TRUNC, file.Mode())
+
+				if fileOpenError != nil {
+					return fileOpenError
+				}
+
+				defer func() {
+					if fileOpenError := extractedFile.Close(); fileOpenError != nil {
+						panic(fileOpenError)
+					}
+				}()
+
+				var _, copyError = io.Copy(extractedFile, fileReader)
+
+				if copyError != nil {
+					return copyError
+				}
+			}
+		}
+
+		return nil
+	},
+}