diff --git a/.config/nvim/ftplugin/haskell.lua b/.config/nvim/ftplugin/haskell.lua
index 4203462..72fd67e 100644
--- a/.config/nvim/ftplugin/haskell.lua
+++ b/.config/nvim/ftplugin/haskell.lua
@@ -2,3 +2,7 @@ vim.bo.tabstop = 8
 vim.bo.expandtab = true
 vim.bo.softtabstop = 4
 vim.bo.shiftwidth = 4
+
+vim.treesitter.start()
+vim.wo[0][0].foldexpr = 'v:lua.vim.treesitter.foldexpr()'
+vim.wo[0][0].foldmethod = 'expr'
diff --git a/.config/nvim/lua/plugins/cvs.lua b/.config/nvim/lua/plugins/cvs.lua
index 7e16e11..c3e898e 100644
--- a/.config/nvim/lua/plugins/cvs.lua
+++ b/.config/nvim/lua/plugins/cvs.lua
@@ -2,8 +2,7 @@ return {
 	{ 'airblade/vim-gitgutter' },
 	{ 'tpope/vim-fugitive' },
 	{
-		'sindrets/diffview.nvim',
-		dependencies = {'nvim-lua/plenary.nvim'},
-		opts = {}
+		'dlyongemallo/diffview.nvim',
+		version = '*'
 	}
 }
diff --git a/.config/nvim/lua/plugins/debugging.lua b/.config/nvim/lua/plugins/debugging.lua
index 35a5694..1712efe 100644
--- a/.config/nvim/lua/plugins/debugging.lua
+++ b/.config/nvim/lua/plugins/debugging.lua
@@ -45,11 +45,5 @@ return {
 			  },
 			}
 		end
-	},
-	{
-		'vim-vdebug/vdebug',
-		config = function()
-			vim.g.vdebug_options = { port = '9000'  }
-		end
 	}
 }
diff --git a/.config/nvim/lua/plugins/development.lua b/.config/nvim/lua/plugins/development.lua
index 90eaadd..8b43924 100644
--- a/.config/nvim/lua/plugins/development.lua
+++ b/.config/nvim/lua/plugins/development.lua
@@ -27,26 +27,25 @@ return {
 		end
 	},
 	{ -- Tag bar.
-		'liuchengxu/vista.vim',
-		lazy = false,
+		'hedyhli/outline.nvim',
 		config = function()
-			vim.g.vista_default_executive = 'nvim_lsp'
+			vim.keymap.set("n", "<leader>o", "<cmd>Outline<CR>",
+				{ desc = "Toggle Outline" })
+
+			require("outline").setup {
+			  -- Your setup opts here (leave empty to use defaults)
+			}
 		end
 	},
 	{
 		'nvim-treesitter/nvim-treesitter',
 		lazy = false,
-		branch = 'master',
+		branch = 'main',
 		build = ':TSUpdate',
 		config = function()
-			require'nvim-treesitter'.setup {
-				ensure_installed = {
-					'haskell', 'php', 'lua', 'css', 'dockerfile', 'html', 'javascript', 'markdown', 'ruby', 'vue'
-				},
-				highlight = {
-					enable = true,
-					additional_vim_regex_highlighting = true
-				}
+			require'nvim-treesitter'.setup()
+			require'nvim-treesitter'.install {
+				'haskell', 'php', 'lua', 'css', 'dockerfile', 'html', 'javascript', 'markdown', 'ruby', 'vue'
 			}
 		end
 	},
diff --git a/.config/nvim/lua/plugins/view.lua b/.config/nvim/lua/plugins/view.lua
index eabf1c5..b7607d3 100644
--- a/.config/nvim/lua/plugins/view.lua
+++ b/.config/nvim/lua/plugins/view.lua
@@ -2,7 +2,7 @@ return {
 	{
 		'sainnhe/sonokai',
 		config = function()
-			vim.g.sonokai_style = "maia"
+			vim.g.sonokai_style = "shusia"
 			vim.cmd('colorscheme sonokai')
 		end
 	},