Form Builder projects enables you to develop job-specific and customizable forms. They collect responses from the users instantly and store the important information through a quiz and also can be used in payments collection. Below I have discussed a list of the Opensource form builders.
1. Elegant iOS form builder in Swift

Elegant iOS form builder in swift is special because of the following features:
- It is elegant has short syntax and its very readable
- It supports changing table-view forms.
- Allows customization of cells and rows to meet ones your specifications.
- Eureka is very flexible and powerful.
- It gets support from a community I.e. GitHub
2. jQuery plugin for drag and drop form creation

JQuery form Builder is a client-side plugin that gives you the ability to construct forms by dragging and dropping. It supports a couple of HTML tags and form fields. It has a companion plugin i.e., form Render that allows you render outcomes of the forms you have created. Features
- It is highly customizable to your specifications.
- It is bootstrap ready but doesn’t depend on bootstrap
- It is translatable
3. JavaScript powered Forms with JSON Form Builder

JavaScript forms is a library that contains plain SDK for Form.io and JavaScript form renderer. It allows rendering of the JSON schema and also rendering within your applications by the use of JavaScript. This library has the following benefits
- Nested Layouts, Select. Input masks, components and data/time.
- It contains a Whole JavaScript API and an addition of SDK library on top of Form.io
- Allows JavaScript implementation using modern practices and ES6.
4.Flutter_ form_ builder

Flutter form builder helps you construct data gathering forms in Flutter by getting rid of boilerplate required to construct a form, react to modifications, validate fields and gathering of last user inputs.
5.Formeo Drag & Drop Form Builder

Formeo is an extendable form creator that is jotted in vanilla JavaScript. It accomplishes a lot of feature requests that are collected for the plug-in. Features
- Controls API
-Builds forms that have interactive maps and signature pads -It clones and extends built-in controls
- External Data
-Its data is dynamic with remotely loaded choice options. -Session information used in the forms like name
6. React Form Builder

React Form Builder is an absolute react form builder. It interfaces to a json endpoint so that it loads and saved the produced forms. This toolbox consists of 16 items for assembling data and everything from signature boxes to star rating. For the form creator to look pretty you need to use other dependencies apart from React I.e Bootstrap, FontAwsome and jQuery.
7. Laravel Collective HTML/Form Builder

LaravelCollective HTML/Form Builder comes loaded with FORM and HTML generators that allows easy handling and management of forms that are in the blade files and also intricate model committed to the forms.
8. Formtastic

Formtastic it’s a Rails FormBuilder DSL that makes it easy to build readily stylable, beautiful and readily available HTML forms. Features
- It can cope belongs to associations rendering a couple of radio inputs to choose from.
- It contains internalization.
- It handles real life stuff like inline error messages, inline hints and help text.
9. Django_Forms_builder

Django is an application that is highly reusable and gives ability got administrators build their forms around the admin interface. It also has options to control the people that gets email notifications after a form’s handover. It supports the following Html 5 features:
- Date fields
- Url fields
- Number fields
- Email fields
- Placeholder attributes
10. The Form.io Form Builder

Form.io.Form Builder contains form constructing ability to Angular.js app. This form constructor aim is to build JSON object description of a form. An Angular.js JSON renderer for Form.io is meant to be used together with Form.io to give a dynamic JSON form rendering proficiency. CLICK FOR MORE INFORMATION
11. Formoid

Formoid is an intuitive, powerful and simple bootstrap form creator for speedy web form progress, embedding and wireframing. It allows you to create surveys, signup forms and event registrations. No more coding Metro, modern flat bootstrap themes, retina ready, fully responsive, pure CSS styled all you require to come up with the best forms. CLICK FOR INFORMATION
12. Orbeon-forms

Orbeon Forms are used in building and deployment of web forms. It deals with huge forms with extensive collections and complex validation of forms, all circumstances typical of government or enterprise. It carries out the W3C Xforms quality and its accessible in a free community edition. Its forms are utilized worldwide in industries such as banking, healthcare, government, education and telecom.
13. Antd-form-builder

Antd-form-builder is a little helper with less than 500 lines of source instructions for constructing forms that have ant.design and React easily and still use indigenous antd form API. Antd-form can’t be utilized as editable form but can display read-only data with form pattern. It supports V4 and V3 versions of antd
14. React-native-form-builder

React native form builder is a form management library that has advanced features. Features
- It manages, trails state and worth of domains.
- Utilizes nativebase components
- It supports nested forms and custom validations.
- It produces form domains UI
- It automatically controls focus to bordering domains on submit.
15. Formulate

Formulate allows you to design forms using Umbraco. It is a an opensource builder that dynamically creates a form that can be used on a website. Features
- It builds forms by increasing any list of domains
- It allows sending of electronic mails on form handover.
- Formulate contains folders for validations, forms data values etc. for easier organization
- Its form templates are highly customizable and extensible.
16. Laraform

Laraform is a library with an aim of being the most appreciated builder tool for web builders. It enhances cooperation by homogenizing the building of forms this increases efficiency by getting rid of a lot of monotonous work. It has a fair community edition. Features
- Has two-sided validation.
- Repeatable elements.
- It is highly extensible.
- It has over 34 in-built elements.
17. Webform-civicrm.io

Webform-ciVicrm.io is a flexible, powerful, and a user-friendly form constructor for CiviCRM. It is used in:
- applicationcontact,signup,optin and enrolment forms.
- Contrinbution and membership forms
- Data entry forms for volunteers and staff
Features
- It creates and updates contacts and build relationships between them
- Accepts credit-card payments for memberships, events and contributions.
- It customizes mails and sets security for the those who can access forms.
18.FORMIUM

Formium is an API-first, automation tool, and headless online form creator used by high performance groups. You can use it to render your forms and surveys within your websites and applications utilizing the existent React elements. It is a drag and drop tool that handles dynamic data and composite business logic.
19.FormSG

FormSG is a form constructor application that is created, open sourced and Supported by open government products team of the Singapore government technology agency. Features
- It contains over 15 different form domain types including email, mobile, tables and attachments.
- It has automatic emailing of delivery for forms constructed with email mode.
- Verified mobile phone and email domains through integrations with AWS SES and Twilio
Conclusion
The above are the top best OpenSource Form Builder projects that you can access on GitHub. What you need to do is just choose one that suits your needs.