maps.js. Uses ymb/yms module system (https://github.com/yandex/ymb)

browserDetection.js

// code from https://api-maps.yandex.ru/2.1.73/map.js?callback=__jsonp_ymaps_map&mode=release&flags=

// see it live - https://yandex.com/maps/?ll=150.854710%2C-35.491643&z=7

// "import mapping"
["theme.browser.current", ".v", function (ym) {
    var browser = ym.env.browser,
        mapper = browser.eventMapper,
        browserEngineLowerCase = browser.engine.toLowerCase(),
        availableEngines = {
            webkit: 'theme.browser.webkit',
            // .....
            gecko: 'theme.browser.gecko'
        },
        result = [
            'util.extend',
            'map.metaOptions',
            'domEvent.override.common',
            'mapEvent.override.common'
        ];

    if (mapper == 'pointer') {
        result.push('domEvent.managerOverrides.pointers', 'domEvent.multiPointer.override', 'domEvent.pointer.override');
    } else {
        result.push('domEvent.managerOverrides.touches', 'domEvent.multiTouch.override', 'domEvent.touch.override');
    }

    // Настройки по конкретным браузерам.
    if (browserEngineLowerCase in availableEngines) {
        result.push(availableEngines[browserEngineLowerCase]);
    } else {
        result.push('theme.browser.unknown');
    }

    return result;
}],

engineSelection.js

// another "mapping"
["theme.browser.webkit", ".C", function (ym) {
    var isMobile = ym.env.browser.isMobile || ym.env.browser.isTablet;
    var isWindowsYabro = ym.env.browser.name == 'YandexBrowser' &&
        ym.env.browser.osFamily == 'Windows';

    return [
        isMobile || ym.env.browser.isSafari || isWindowsYabro ?
            'layer.tileContainer.DomContainer' :
            'layer.tileContainer.CanvasContainer'
    ];
}]

graphicsDetection.js

// this is more about polyfills
["graphics.render.detect.all", "5N", function (ym) {
    var depends = [];
    if (ym.supports.graphics.hasCanvas()) {
        depends.push('graphics.render.canvas.support');
    }
    if (ym.supports.graphics.hasSvg()) {
        depends.push('graphics.render.svg.support');
    }
    return depends;
}],

inversePredictor.js

// This is more about IoT - this module would be injected into `layout` registry once someone will try to use it. 
ym.modules.define({
        name: "theme.islands.geoObject.layout.StretchyIcon", // module name
        key: "islands#stretchyIcon",                         // key 
        storage: "layout",                                   // "registry"
        depends: ["util.dom.element", "util.dom.style", "util.dom.className", "util.math.areEqual", "templateLayoutFactory", "placemarkNew.layout.html", "Monitor", "shape.Polygon", "geometry.pixel.Polygon", "system.browser", "util.css", "util.string"],
        declaration: function() {.....}                      // code
});