Karabiner-Elements: Alt-Tab support and CTRL-Windows key swap.

ke_at_cws.json

{
    "description": "Windows-like key mapping: Control⇄Command + Alt+Tab cycling",
    "manipulators": [
        {
            "from": { "key_code": "left_control" },
            "to": [{ "key_code": "left_command" }],
            "type": "basic"
        },
        {
            "from": { "key_code": "right_control" },
            "to": [{ "key_code": "right_command" }],
            "type": "basic"
        },
        {
            "from": { "key_code": "left_command" },
            "to": [{ "key_code": "left_control" }],
            "type": "basic"
        },
        {
            "from": { "key_code": "right_command" },
            "to": [{ "key_code": "right_control" }],
            "type": "basic"
        },
        {
            "from": {
                "key_code": "left_option",
                "modifiers": { "optional": ["any"] }
            },
            "to": [
                {
                    "set_variable": {
                        "name": "option_held",
                        "value": 1
                    }
                },
                {
                    "key_code": "left_command",
                    "lazy": true
                }
            ],
            "to_after_key_up": [
                {
                    "set_variable": {
                        "name": "option_held",
                        "value": 0
                    }
                },
                {
                    "key_code": "left_command",
                    "lazy": true,
                    "modifiers": []
                }
            ],
            "type": "basic"
        },
        {
            "conditions": [
                {
                    "name": "option_held",
                    "type": "variable_if",
                    "value": 1
                }
            ],
            "from": {
                "key_code": "tab",
                "modifiers": { "optional": ["any"] }
            },
            "to": [
                {
                    "key_code": "tab",
                    "modifiers": ["command"]
                }
            ],
            "type": "basic"
        }
    ]
}