A system for mapping between an HTML file and a source file comprising: at least one processor of a computing device comprising a web server; a memory of the computing device; and at least one module causing the at least one processor to: receive source code and/or compiled code adapted to generate an HTML file; in response to receiving an HTTP request for the HTML file, generate the HTML file, including a plurality of output elements and generate metadata that maps at least one output element of a plurality of output elements in the HTML file to a particular location in a particular source file responsible for generating the at least one output element of the plurality of the output elements, the metadata for the at least one output element comprising a path to the particular source file and a start position in the particular source file at which the code that generates the at least one output element is found; and generate and send a response comprising the HTML file and the metadata to a browser on a requesting computer, wherein the browser is adapted to display the source file for a page mapped using a mapping table according to the metadata that is being displayed in the browser. at least one processor of a computing device comprising a web server; a memory of the computing device; and at least one module causing the at least one processor to: receive source code and/or compiled code adapted to generate an HTML file; in response to receiving an HTTP request for the HTML file, generate the HTML file, including a plurality of output elements and generate metadata that maps at least one output element of a plurality of output elements in the HTML file to a particular location in a particular source file responsible for generating the at least one output element of the plurality of the output elements, the metadata for the at least one output element comprising a path to the particular source file and a start position in the particular source file at which the code that generates the at least one output element is found; and generate and send a response comprising the HTML file and the metadata to a browser on a requesting computer, wherein the browser is adapted to display the source file for a page mapped using a mapping table according to the metadata that is being displayed in the browser. receive source code and/or compiled code adapted to generate an HTML file; in response to receiving an HTTP request for the HTML file, generate the HTML file, including a plurality of output elements and generate metadata that maps at least one output element of a plurality of output elements in the HTML file to a particular location in a particular source file responsible for generating the at least one output element of the plurality of the output elements, the metadata for the at least one output element comprising a path to the particular source file and a start position in the particular source file at which the code that generates the at least one output element is found; and generate and send a response comprising the HTML file and the metadata to a browser on a requesting computer, wherein the browser is adapted to display the source file for a page mapped using a mapping table according to the metadata that is being displayed in the browser. <EOS>