AU

Server Side Rendering (SSR) with ASP.NET Core support.

Security using OAuth like Auth0 / authentication and authorization

Electron and Aurelia

Aurelia UX or any other official UI Aurelia plugin

Progressive Web Applications (PWA) and Aurelia (Offline support)

Aurelia Web Components

Lazy-loading routes, and creating site-maps based on routes at startup( master and nested children routes )

SEO in Aurelia (Browser/SSR) / SEO optimization without using SSR and Meta Tags

https://github.com/shahabganji/aurelia-meta

Aurelia Architecture

Reactive programming in Aurelia

Aurelia and Virtual DOM.

@processContent, InlineViewStrategy, compiling your own Views and managing ViewSlots, BindingEngine or EventManager

Using binding behaviors to manipulate binding expressions (e.g. generating form bindings based on json schema’s - Ashley Grant wrote a blog post about this)

Extending/overriding the binding language

multi-rooted apps

Utilizing WebWorkers for background processing

Comprehensive guidelines on when queueMicroTask is needed

GraphQL 

Validation (JSON-based) - build forms from a JSON schema / dynamic-ish form generators

performance optimization

Cypress and Aurelia
https://github.com/bahmutov/cypress-vue-unit-test

Create a new log appender like Colorful
https://www.npmjs.com/package/ololog

Aurelia Linter/Formatter/EditorConfig

Multi level menu
http://bit.do/qwerty66
Aurelia (Sync/Async) theme manager with loading js/css/images/fonts

Aurelia Async binding
https://github.com/zewa666/aurelia-async-binding

Aurelia with SignalR Core

global Client Side error/exception/Logging handling (not with Bluebird)
http://www.mikeobrien.net/blog/client-side-exception-logging-in-aurelia
https://gist.github.com/jdanyow/c15e34b97db84aac5494953acd3fea8d

Support NativeScript/Ionic/Framework7/Electron/LibUI

Write custom Template Controllers

Static site generator like Gatsby or VuePress
https://www.gatsbyjs.org/
https://vuepress.vuejs.org/

Dynamic routing

Animation in Aurelia

Hydration in Aurelia

Aurelia with Firebase integration

Plugin system with CLI

Aurelia Template Compiler/Parser API
https://github.com/vuejs/vue/tree/dev/packages/vue-template-compiler
https://github.com/vuejs/vue-component-compiler
https://github.com/vuejs/component-compiler-utils

Aurelia API/Documentation Generator

Aurelia Persistedstate like Ember Data or Angular Data  Persistence
https://github.com/emberjs/data
https://nrwl.io/nx/guide-data-persistence

Aurelia Store Mock

Auelia Http Client Cache/Mock/Request/Response log

Localization

Auelia Http Client Cache

Aurelia and Docker

Multiple states for Aurelia Store
Aurelia web workers

Aurelia with CSS-in-JS emotion or aphrodite
https://github.com/emotion-js/emotion
https://github.com/Khan/aphrodite

Support extendable CLI like Vue
https://medium.com/vue-mastery/5-vue-cli-3-plugins-for-your-vue-project-df5af357d076

Visual Studio and VSCode integration (Full intellisense support).

Aurelia and Aurelia Store Browser Inspector (Better chrome support)

Mock Back-end like 
https://medium.com/letsboot/the-perfect-mock-backend-to-start-with-an-angular-application-3d751d16614f) and [this](https://jasonwatmore.com/post/2019/05/02/angular-7-mock-backend-example-for-backendless-development) - [Nock](https://github.com/nock/nock), [MockServer](https://github.com/jamesdbloom/mockserver

Aurelia feature management 
https://github.com/willmendesneto/ngx-feature-toggle
https://github.com/fabric8-ui/ngx-feature-flag
https://devblogs.microsoft.com/premier-developer/angular-how-to-implement-feature-flags/

Functional programming with Aurelia