Extremely basic Semantic Version comparison function.

SemVer.js

function SemVer(version) {

    var parsed = String(version).match(/^(\d+)\.(\d+)\.(\d+)$/) || [];

    this.string = version;
    this.version = [
        Number(parsed[1]) || 0,
        Number(parsed[2]) || 0,
        Number(parsed[3]) || 0
    ];

}

SemVer.prototype = {

    compare: function (version) {

        var semver = new SemVer(version);

        return (
            this.version[0] - semver.version[0]
            || this.version[1] - semver.version[1]
            || this.version[2] - semver.version[2]
        );
        
    },

    toString: function () {
        return this.string;
    }

};

SemVer.compare = function (version1, version2) {
    return (new SemVer(version1)).compare(version2);
};