MarkOrc

local TAG_MATCH  = "[%a%d#=_-]+";

function tagize(tag)
    if tag:sub(1, 2)=="</" then
        local pos1, pos2 = tag:find(TAG_MATCH);
        return {
            tag  = tag:sub(pos1, pos2),
            mode = 0,
        };
    else
        local pos1, pos2, name, attribute = tag:find("("..TAG_MATCH..")=("..TAG_MATCH..")");
        return {
            tag  = name,
            mode = 1,
            attribute = attribute,
        };
    end
end

function tokenize(str)
    local result = {};
    while true do
        local pos1, pos2 = str:find("<[/]*"..TAG_MATCH..">");

        if pos1==nil then
            if #result==0 then
                return str;
            end

            if #str>0 then
                result[#result+1] = str;
            end

            return result;
        end

        local normal = str:sub(0, pos1-1);
        if #normal>0 then
            result[#result+1] = normal;
        end
        
        local token = str:sub(pos1, pos2);
        if #token>0 then
            result[#result+1] = tagize(token);
        end

        str = str:sub(pos2+1);
    end
end

-- This is an example of MarkOrc
tokens = tokenize("This text is <color=#FF0000>red</color> and rad lovely");

-- `tokens` is now 
--[[{ "This text is ", {
    attribute = "#FF0000",
    mode = 1,
    tag = "color"
  }, "red", {
    mode = 0,
    tag = "color"
  }, " and rad lovely" }]]