1. Technologies Which Can be Helpful for Web Application Development..
This Are Top Technologies Which would be helpful for you for web app development...
Technologies
CSS Drupal
ASP.NET PHP
WebObjects Ruby, including Ruby on Rails
Ajax Java
ColdFusion Django
CSS - Cascading Style Sheets :-
Cascading Style Sheets (CSS) is a style sheet
language used for describing the presentation
semantics (the look and formatting) of a document
written in a markup language. Its most common
application is to style web pages written in HTML and
XHTML, but the language can also be applied to any
kind of XML document, including plain XML, SVG and XUL.
Ajax (programming) :-
Ajax is not a single technology, but a group of
technologies. HTML and CSS can be used in
combination to mark up and style information.
The DOM is accessed with JavaScript to
dynamically display, and to allow the user to
interact with the information presented.

2. ASP .NET :-
ASP.NET is a Web application framework developed and
marketed by Microsoft to allow programmers to build dynamic
Web sites, Web applications and Web services. It was first
released in January 2002 with version 1.0 of the .NET
Framework, and is the successor to Microsoft's Active Server
Pages (ASP) technology. ASP.NET is built on the Common
Language Runtime (CLR), allowing programmers to write
ASP.NET code using any supported .NET language.
WebObjects :-
WebObjects is a Java web application server from Apple Inc., and a
web application framework that ran on the server. It was available at
no additional cost. Its hallmark features were its object-orientation,
database connectivity, and prototyping tools.
Adobe ColdFusion :-
ColdFusion is the name of a commercial rapid web application
development platform invented by Jeremy and JJ Allaire in 1995.
(The programming language used with that platform is also
commonly called ColdFusion, though is more accurately known as
CFML.) ColdFusion was originally designed to make it easier to
connect simple HTML pages to a database.

3. Drupal :-
Drupal is a free and open-source content
management framework (CMF) written in PHP and
distributed under the GNU General Public License. It
is used as a back-end system for at least 2.1% of all
websites worldwide ranging from personal blogs to
corporate, political, and government sites including
whitehouse.gov and data.gov.uk.[8] It is also used for
knowledge management and business collaboration.
PHP :-
PHP is an open source general-purpose server-side scripting
language originally designed for Web development. It is one of
the first developed server-side scripting languages to be
embedded into an HTML source document rather than calling
an external file to process data. The code is interpreted by a
Web server with a PHP processor module which generates the
resulting Web page.
Ruby & Ruby on Rails
Ruby is a dynamic, reflective, general-purpose object-
oriented programming language that combines syntax
inspired by Perl with Smalltalk-like features. It was also
influenced by Eiffel and Lisp. Ruby was first designed
and developed in the mid-1990s by Yukihiro "Matz"
Matsumoto in Japan.
Ruby on Rails, often shortened to Rails, is an open
source full-stack web application framework for the
Ruby programming language.

4. Java :-
Java is a programming language originally developed by James Gosling at
Sun Microsystems (which has since merged into Oracle Corporation) and
released in 1995 as a core component of Sun Microsystems' Java platform.
The language derives much of its syntax from C and C++, but it has fewer
low-level facilities than either of them. Java applications are typically
compiled to bytecode (class file) that can run on any Java virtual machine
(JVM) regardless of computer architecture.
Django :-
Django web Framework is an open source Web 2.0
application framework, written in Python, which follows the
model–view–controller architectural pattern. It was
originally developed to manage several news-oriented sites
for The World Company of Lawrence, Kansas, and was
released publicly under a BSD license in July 2005; the
framework was named after guitarist Django Reinhardt.
Here is the list of the technologies which you can use for web app development..