Modernise Your Legacy Software Without Disruption

We specialise in upgrading old business-critical systems (like Access databases, VB6 apps, and other outdated tools) into maintainable platforms using .NET. Delivery can be AI-assisted. The job is to keep the business running.

Is your problem one of these?

  • The person who understands the system has left
  • The technology is no longer supported
  • Nobody wants to change it because they're afraid of breaking it
  • You need to modernise it but can't stop the business

What We Upgrade

We modernise all types of legacy business systems

Microsoft Access or Excel/VBA systems
VB6 and legacy .NET apps
Classic ASP or internal web portals
SQL Server databases with performance issues
Manual workflows reliant on outdated tools

Start with the stack you have

If you already know the product, go there. If you do not, the list above is enough to start a conversation.

CMS

DNN / DotNetNuke

Stuck on DNN 7, 8 or early 9. Upgrade in place, or move off, without a rebuild from scratch.

DNN migration

Umbraco 7 and 8

v7 ended 30 Sep 2023, v8 ended 24 Feb 2025. No in-place climb. Content can migrate; templates and packages are a rewrite.

Umbraco migration

Kentico Portal Engine / 12

Portal Engine support ended in 2023. There is no web-part converter. Kentico 13 itself ends 31 Dec 2026.

Kentico migration

Sitefinity

13.3 LTS (last Web Forms home) retired April 2026. 15.4 LTS is still .NET Framework 4.8.

Sitefinity upgrade

Sitecore XP / XM

Current is 10.5, still Framework 4.8.1. SitecoreAI is not an XP upgrade.

Sitecore migration

Optimizely / Episerver

Same vendor after the 27 January 2021 rebrand. CMS 11 is off routine patches; 11 to 12 is Framework to Core.

Optimizely upgrade

Orchard CMS 1.x

Orchard 1.x is Framework. Orchard Core is a rewrite. There is no in-place upgrade.

Orchard migration

Ecommerce

AbleCommerce

Gold is vendor end-of-life (May 2026). 7 and Gold can go to 9 as data plus a re-skin, not a patch.

AbleCommerce migration

Ucommerce

Classic on Umbraco 7/8 or Sitecore is not Umbraco Commerce. Next Gen takes the catalog; pipelines do not paste.

Ucommerce migration

nopCommerce 3.x / 4.0

3.x is Framework MVC5. 4.00 is still Framework. Official climb is stepwise SQL to 4.30, then migrations.

nopCommerce upgrade

Smartstore

Classic Smartstore.NET is Framework 4.7.2. Anything older than 4.2 has no supported jump to current 6.4.

Smartstore upgrade

Virto Commerce v2

v2 has been unsupported since 1 June 2022. Current v3 is on .NET 10.

Virto Commerce upgrade

Custom and desktop

ASP.NET Web Forms

Web Forms is not calendar-EOL and does not exist on ASP.NET Core. Stay on supported Windows, or rewrite screens.

Web Forms migration

.NET Framework

4.8.1 is still supported on Windows. The usual deadline is the Server under it, or a library that will not port.

.NET Framework migration

SharePoint 2016 / 2019 intranet

Extended support ended mid-July 2026. No ESU. Destinations are Subscription Edition or SharePoint Online.

SharePoint intranet upgrade

Silverlight

Support ended 12–13 October 2021. There is no converter. The work is a rewrite.

Silverlight migration

WinForms (web-enable)

WinForms is not end-of-life. .NET 10 still ships it. Hybrid is not a public website.

WinForms web-enable

Access

Ageing Access or Excel-VBA. Assess first: keep and harden, SQL Server behind Access, or replace with a .NET app.

Access development

Why Upgrade?

The benefits of modernising your legacy systems

Break Free from Tech Debt

Eliminate maintenance headaches and reduce operational risks

Boost Performance & Security

Modern platforms with enterprise-grade security and speed

Integrate with Modern Platforms

Connect seamlessly with cloud services and modern APIs

Future-Proof Your Operations

Built on modern frameworks that evolve with technology

Our Approach

A proven 4-step process for seamless legacy modernisation

1

Audit & Strategy

System review and risk analysis to plan the upgrade path

2

Modern Design

UI/UX redesign and clean architecture where the interface is part of the job

3

Build

Iterative development

4

Test and Transition

Parallel testing and handover with minimal downtime

Tools We Use

Modern technology stack for reliable, scalable solutions

.NET 8 & SQL Server

Enterprise-grade Microsoft technology stack

Azure or AWS

Scalable cloud hosting and services

AI-assisted delivery

Not a product name. Delivery can be AI-assisted.

Modern Frontend

Blazor, React, Razor Pages

Why CoSource?

The expertise and approach that makes us the right choice for your legacy upgrade

Microsoft and .NET experience

Team experience on Microsoft technologies and legacy system migration.

Transparent Agile Delivery

Clear communication and regular updates throughout your project

Trusted with Core Systems

Proven track record with business-critical internal systems

Australian team

Sydney-based. We work with Australian organisations on systems that have to keep running.

Still running on legacy software?

Thirty minutes. Bring the name of the system and whether it has to keep running while you change it.